Carpet That’s Seen But Not Heard

Sharni Verity, Marketing Executive at Heckmondwike FB, discusses how specifying carpet can address acoustic issues in offices.

One of the most common complaints in office environments is the inability to work due to noise pollution.  Hard flooring, such as timber, tile or laminates can contribute to the problem, especially where an office is open plan or has several storeys.

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Carpets: What a difference colour can make

Carpet - Array

It is an increasingly widely recognised fact that the environment you work in every day has an influence on how productive you are.

Research* has shown that colour in the workplace can encourage creativity, productivity and give a boost to morale.  Some colours have been found to actually raise productivity levels and to minimise fatigue and improve team working.

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Are Testing Regimes for New Construction Products Fit for Purpose?

This is a guest post by Steve Broadhurst, Technical Services Manager at Jablite, looking at alternative ways of testing and certifying new building products.

At EcoBuild this year, Richard Lee, managing director at Jablite, was on a panel to discuss ‘Maximising Building Performance – could manufacturers do more?’

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Let’s Not Be Passive About Phase Change Materials (PCM)

Phase Change Materials

This is a guest post by Jeremy Sumeray of Armstrong Ceilings, looking at the benefits of using of PCMs in ceiling products.

“Greening” buildings is not a modern phenomenon. Using elements of them to conserve energy and their impact on the environment is a practice that goes back to prehistoric times when cavemen intuitively recognised the value of thermal mass in creating a comfortable indoor environment.

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In the Zone with Flooring Design

Zonal Flooring Design

This is a guest post by Abby Chandler, Marketing Manager at Heckmondwike, looking at the use of zoning in flooring design.

Open plan spaces continue their popularity for offices, schools and colleges, with architects looking for clever ways to create demarcation without partitions and barriers. This is where specifiers are using carpet creatively to achieve their aspirations.

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Specifications – Poacher Turns Gamekeeper

Specifications – Poacher Turns Gamekeeper

This is a guest post by Stephen Walton, a Director of Schumann Consult, who joins us to share his thoughts on specification writing.

For twelve years I have been working as a specification consultant with Davis Langdon Schumann Smith and last summer, I was delighted to team up with Nick and Mark Schumann at Schumann Consult.

Over that time I have been privileged to work on some wonderful projects and with a number of exceptional architectural teams.

Have I got a favourite, well yes, unquestionably the refurbishment of the Royal Festival Hall with Allies and Morrison, which started for me around 2004.

Looking back on that, I wonder if one of the reasons I had that connectivity with that particular project was in fact my contracting background in refurbishment, which is the subtext for this article.

Specification consultants, in common with most things in this world, come in all different shapes and sizes, and of course, professional backgrounds.  Predominant, understandably, were former architects and to a lesser extent, cost consultants.

My background however was construction procurement, or as we used to call it years ago, ‘Buying’!

Hence, the perhaps over-used analogy of Poacher turned Gamekeeper.

I have certainly no intention in boring you with my career path since 1976, other than to mention my spell with Walter Lawrence/Hall & Tawse between 1983-1998 which formed the mainstay of my purchasing career, and also gave me a background in joinery when I was responsible for an in-house joinery shop for a number of years during that period.

During that time, as you can doubtless imagine, I encountered many specifications, some good but most not.

Being on the receiving end of specifications does serve to focus the mind on how to make them better when you are the person chiefly responsible for their composition.

The most common problem was not that they were technically flawed or particularly riddled with obsolete standards, but the fact they were poorly edited with what one might refer to as ‘boilerplate’ text, which often ends up in the need to err on the side of caution when tendering.

So, when I am writing a specification now, I ask myself whether I have left any opportunities for variations if I was the person receiving it in the procurement team.

With all that said, I also believe it not particularly helpful to create a document that one could describe as the ‘sum of all fears’, packed with the consultant’s anecdotal baggage of catastrophic events from a bygone era.

When I first began my specification consulting career in 2002, it was gratifying to immediately realise that it was in fact completely bespoke specifications we were being asked to draft, informed by face to face engagement with the designer, rather than a perfunctory or volume churn of the type of document I referred to earlier.

My years in contracting also made me appreciate the role manufacturers and specialists can play in ensuring that the specification is commercially astute and technically correct. I frequently liaise with manufacturers and would like to put on record my sincerest appreciation of their almost universally good-hearted and best-intentioned help.

My contracting background also gives me some empathy with the contractor, insofar that for years, particularly in the London refurbishment sector, the competitive tendering process entailed going in at next to nil mark up whereby on occasions, it was the contractor dropping the biggest clanger who ended up securing the project! It then fell upon the procurement team to try their best to exploit shortcomings in specifications and secure buying margins on materials and subcontracts to accrue some sort of return.  This was just a recipe for corner cutting and adversarial relationships.

It is against this background that on the occasions I meet with contractors, I am at pains to stress that our document is not meant to be a trap or to set a bar at far too high a standard, but instead its intent is to hopefully accurately convey our clients’ design intent and aspiration to deliver the best project we can as a team.

It is against that background that documents produced for Henry J Lyons’ stunning Central Criminal Courts building in Dublin were described as being the best series of subcontractor proposals/returns the contractor had ever received. I mention that in no remote context because I drafted them, but because they were expressly bespoke and as a consequence managed to convey the quality aspiration of the client architect and his employer.

When setting about a new spec, there is typically a number of what I can only describe as ‘hot-spot’ topics about which I try to raise an awareness of very early on.

These include and are not limited to:

  • Finishes to in situ and precast structural concrete
  • Slip resistance of floors and paving
  • Design responsibility
  • Natural stone
  • Tolerances
  • Specifying elements, not finishes.

One in particular, which always baffles (and does not form part of the aforementioned) is that of painted doorsets. Architects will always strive for a visually flawless finish best achieved by a full factory, pre-finish. By contrast, the contractor will move heaven and earth to avoid this because it is next to impossible to achieve an adequately indiscernible touch-up of damage sustained on site before handover.

What is the answer? – there isn’t one, but there is at least awareness to consider it before it turns septic at practical completion.

I hope this account might, if nothing else, convey the benefits of ‘specification consultancy’ rather than ‘specification writing’ and go some way to illustrating why many designers elect to retain specification specialists on signature projects.

I often describe our work as ‘another pair of eyes’ for the designer before their documents go external, and whilst to the uninitiated, writing specs for a living might be perceived as akin to watching a newly emulsioned wall slowly drying, it can and has been enormously rewarding.

StephenWaltonAbout the Author: Stephen Walton is a Director of Schumann Consult with over 30 years experience in the construction industry, 14 of which as a Specification Consultant for many of the worlds leading Architectural practices. For further reading, check out the Schumann Consult blog.


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Should Underfloor Heating be Considered for Upper Floors?

Underfloor Heating

The question?

You have a project, be it renovation or new-build and are considering upgrading to the luxury of underfloor heating for the ground floor as you know that it is a sign of quality but should you also be considering it for the upstairs?

The use of underfloor heating upstairs is becoming more common, but an understanding of the advantages this brings could be helpful in making decisions...


Underfloor Heating from below

Efficiency of the heating system

Perhaps the most compelling reason for using underfloor heating within a concrete or screed is the effect it has on the efficiency of the heating system, whether it be a conventionally fueled or renewable energy based one.

Underfloor heating should only be considered when the insulation and airtightness of the building has been addressed and is sufficient to ensure this type of heating system is suitable.

Typically the temperature of the water within a traditional radiator based system is around 65-75oC, compared to 35-45oC in the pipes within a typical concrete or screed floor (please use the terms concrete and screed interchangeably for the purpose of this post).

By decreasing the temperature of the water produced by the heating system, less energy is required to provide the heating to a building.

This is great for the ground floor as it is generally relatively simple to have a concrete ground floor.

Upper floors are typically made of timber and therefore require a suspended under floor heating system, these can be based on the pipes being installed under a traditional timber deck, usually tongue and groove, chipboard or plywood boards. Timber boards understandably act as an insulation layer and therefore a higher temperature is again required, often back up to the 65-75oC range, making this type of system often no more efficient than radiators.

Ideally to get the same efficiency as a concrete ground floor it makes sense to use concrete at first floor and above.

The introduction of the Renewable Heat Incentive (RHI), increasing performance requirements of Part L of the Building Regulations and the Government’s drive to see all new buildings built to Zero carbon standards within the next few years will see a rapid rollout of heat-pump systems. These are ideal for use with under floor heating as they efficiently produce heat at the lower temperatures associated with underfloor heating.

It’s understood that where underfloor heating is used on the ground floor and radiators on upper floors the heating system will be required to produce higher temperature water for the radiators that is then blended with colder water for the ground floor, thus detrimentally affecting the efficiency of the system, especially where heat-pumps are involved.

Therefore to maintain the efficiencies of a heat-pump system it is sensible to link the system to under floor heating on all floors.

Thermal mass

Many of today’s buildings are constructed using lightweight materials, be it light weight blocks, timber frame, light gauge steel frame or SIPs or using techniques that effectively isolate the thermal mass from the interior of the building, for example ICF or plasterboard linings mounted on battens or “dot and dab” effectively introducing an insulation layer of polystyrene or still air between the internal atmosphere and the material that has the mass.

Thermal mass helps to buffer heat losses and gains, heat loss in the winter and overnight and solar gains in the summer, making for a more comfortable internal environment without spikes in temperature, up or down and the resulting affect this has on the occupants and how hard the heating system has to work.

By introducing thermal mass into the project in the form of concrete floors into any of building systems mentioned above enables this buffering system to assist in regulating the internal temperature.

To get the best out of the thermal mass and an underfloor heating system, appropriate floor coverings should be chosen, the denser the better, including all types of tile, dense timber, polished concrete, carpets and underlays designed for use with underfloor heating, etc.


Incorporating underfloor heating eliminates space consuming radiators and their effect on room layouts. Radiators should not be placed under windows as, even with triple glazing, these will be the worst performing areas of the wall and people often have curtains that extend right to the floor, this allows a lot of the heat generated to escape. Having radiators on other walls will always then compromise the choice of placing furniture.

In discussions with an architect recently, it was estimated that the use of radiators effectively reduced the useable space within a room by about 10%. For self-builders, this means that by using under floor heating, their rooms are effectively bigger for the same foot print and for developers, their footprints could be reduced but they would still be offering the same useable area for each room, this benefits both type of builder.

The efficient utilization of space is vitally important in many other types of buildings, including: apartments, student accommodation, hotels, motels, care homes, etc.


The use of any underfloor heating system requires a change in thinking about how the system operates as they tend to have longer heating up and cooling down periods. This necessitates patience and understanding of how the system best works.

A properly programmed, zoned thermostat controlled heating system will ensure that rooms are very comfortable during the course of the day and night. This is especially the case with heat pumps that work most efficiently over longer periods and are therefore ideally suited to underfloor heating.


With the continued increasing uptake of under floor heating, especially in conjunction with heat pumps, the case for taking it “upstairs” needs to be defined. This is not just down to the practicalities of how to install the pipes, but also what the effects are on the efficiencies of running the building and how this fits with the continued tightening of regulations to make buildings of all types more efficient.

Being able to easily install a concrete floor upstairs is key to ensuring the best efficiencies are achieved from any heating system chosen to be combined with underfloor heating.

About the author: Chris Holt is the MD of CDI Innovative Construction Materials Ltd, which brings Lewis® Decking to market to create concrete or screeded suspended underfloor heating, acoustic, wet-room and fire-proof floors. He is also a BRE registered Code for Sustainable Homes Assessor.

Checkout their website or Twitter feed or view their product information on SpecifiedBy.

Loft Insulation isn’t Working

Loft Insulation

In the UK, there are 23 million houses with lofts and several million non-domestic properties that also have loft spaces.

According to Government figures, around 15 million of the houses have insulation of over 100mm (though often nowhere near the current building regulations of 270mm) but there seem to be no figures for insulation levels of non-domestic properties. For many of the buildings without adequate insulation, access and storage requirements are cited as the reason, because the owners want to be able to access M&E equipment or they want to use the loft as a space for storage.

Well, at least we have over half of the country’s properties with properly working insulation... except, alas, no we don’t.

That’s because recent research by the National Physical Laboratory and Carbon Trust shows that in 80% of insulated properties, the insulation isn’t working, and that the reduction in thermal resistance from what is expected is at least 50%.


Loft Insulation

Source: NPL

The issue is one of compression: for mineral wool-type insulation, it needs to retain its full depth to work properly. Ask the insulation manufacturers how performance is diminished if the insulation is squashed and they will simply tell you that it’s an abuse of the product to squash it, which is correct.

But, in both the residential and non-residential sectors, insulation is regularly squashed. Carbon Trust sponsored the biggest ever survey of loft users, with 6,000 responses, and the results are eye-watering:

  • 82% use their loft for storage
  • 78% say the loft is greater than half full
  • 76% say loft storage is important or essential
  • 65% have fully or partially boarded their loft at joist height (typically squashing or removing the insulation down to 75 or 100mm)
  • only 26% knew that squashing loft insulation was bad for it.

In effect, 82% of lofts users have compromised their insulation, and only 26% of users knew this was reducing its effectiveness.

What is the effect on the U-value from compressed insulation? Tests by the National Physical Laboratory on the market-leading mineral wool insulation found:

  • Compression from 270mm to 100mm (4” joist height) results in a reduction of the thermal resistance of 50%
  • Compression from 270mm to 75mm (3” joist height) results in a reduction of the thermal resistance of 61%.

Add this up over the whole UK and this is a massive in-use reduction, equivalent to switching on one whole power station. After millions of pounds of CERT and CESP funding for insulation over the past few years, this is depressing reading.

What are the alternatives?

Historically, one way to protect the insulation is to raise the joist with extra timber. The materials for this are relatively cheap, but the labour is not, and the timber places significant extra weight on the joists.

Another historical approach is to lay rigid foam insulation, with boards placed, or bonded, above these. But fitting these in a loft is not easy; large insulation boards can be difficult to get into the loft, they have to be cut to size in the loft and gaps between them, and the (often irregular) joists need to be carefully sealed. It is also preferable to leave space for a flow of air between the top of the insulation and the underside of the boards, to allow moist air to be removed and stop any risk of condensation, which may require extra timber in addition to the boards.

More recently, a suite of raised loft decking products have come to market, which all consist of supports or a supporting structure that lifts the boards up above the insulation by between 180-280mm. Some of these are strong enough to walk upon, whilst others are more for storage; some allow for an air-gap between the insulation and the boards whilst others do not; some also allow for cables and other services to be raised above the insulation too, whilst others do not.

They are typically sold by LoftZone, B&Q and Wickes, and some builders merchants. Increasingly they are being specified as standard by architects for new build and retrofit, conscious that without them, the insulation is going to be working well below par.


So, in summary, when designing energy efficiency programmes, it’s necessary to quite simply assume significant in-use reduction factors for loft insulation unless mitigating measures have been put in place.

Most of the UK’s loft insulation simply isn’t working as well as promised, and many people refuse it in the first place as they value access and storage more highly.

You wouldn’t specify external wall insulation on a building and then not insist upon render on the outside to protect it from damage.

So why would you not protect loft insulation from damage, too?

About the Author: Dave Raval is CEO of LoftZone, which has brought to market a raised loft deck for safe access and/or storage purposes for both domestic and non-domestic properties.

Check out their website, Facebook, Twitter and YouTube channels, or download their product information from SpecifiedBy.

Would you like to contribute to our blog? More information here.

Guidance for Insulating Older Properties

There are many ways to thermally upgrade an older property; loft insulation, cavity wall insulation and external wall insulation known as EWI or ETICS (External Thermal Insulation Composite System).

This article highlights some of the key areas to pay particular attention to when doing so.

Wall Insulation

Before work commences on a EWI system installation it is always best to check with the local authority planning department as a EWI system can dramatically change the look and feel of a building and may require planning permission.

A check should be made with the building control department to see if a certain type of insulation maybe required. For example, if the building is within 1m of another building, mineral fibre insulation may be required to comply with fire regulations.

If there are any large cracks in the substrate then it would be advisable to ask a structural engineer to give a report to ensure that the substrate is in a sound condition and that any potential repairs and damp issues are resolved prior to installation of a EWI system.

Other considerations would be the relocation of domestic services into the property, such as electricity, gas, telephone and satellite installations, as these are often fixed to the external walls of older properties. Although some services can be boxed in to hide them, access maybe required by the utility company for maintenance.

Air vents, boiler ducts, outside taps  washing lines and external lights all need to be relocated or extended to the surface of the EWI system and fixing points inserted in the system to take the newly positioned services.

Ventilation to the eaves of the soffit will need to remain open so the system may need to be terminated short of the soffit or chamfered back to allow passage of air to the loft space.

Overhangs such as parapet walls gable ends and other projections from the walls will need to be allowed for and a suitable weather tight detail designed to ensure weather tightness.

Sheds, and fences, may need to be relocated as these often abut property walls. And canopies, lean-tos and conservatories may need fabricated flashings made for them.

Window cills will need to be extended, and in the case of UPVC windows, the original fabricator can often provide these to suit the window system used on the property. It is important to allow a overhang to the face of the finished render system and this is generally around 35mm.

Identification of the existing damp course must be carried out as this should not be bridged by the new EWI system and should be at least 150mm – 200mm above any surface finish such as decking or paving.

If no damp course is present, then consideration should be given to one being injected into the substrate for masonry situations, as this will be much easier at this stage before the application of the EWI system.

A U-Value calculation with a condensation risk should be carried out to establish the buildings current thermal performance and to see what effect the new EWI system would have on the building after installation as grants maybe available to help with the cost of the upgrade.

This calculation would also highlight any potential condensation risks that may affect the building by adding insulation to the external wall, particularly if the cavity has been previously filled with injected insulation.

If the current property already has sand and cement render system installed or pebble dash, this should be checked for potential problems, as these renders can sometimes be unsuitable for the application of an EWI system and advice should be sought from a system manufacturer’s technical department before application of a system.

Design advice and technical help should always be sought from the system supplier / designer prior to application of any system.

About the Author: Steve Webber is Product Manager at Knauf Marmorit UK GmbH. You can follow them on Twitter, download their product information on SpecifiedBy or find Steve on LinkedIn.