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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Building Regulations, British Standards and an Information Paper – What do they all mean for Stair Nosings?

This is a guest post from the technical team at Quantum Flooring Solutions. You can find them on SpecifiedBy, Twitter or visit their website here.

There are five documents, which give guidance for the design of stairs (and application of associated Stair Nosings) for use in buildings with public or shared use:

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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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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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A Process for Specification Writing

This is the first in a series of articles aimed at getting architects, technicians and technologists to share more details about their work, their processes, knowledge and expertise.

In this article, Neil Marshall, who is a director at the Design Buro in Coventry, talks us through his process for writing a building project specification.

Specification Writing

Specification writing exists daily in my work, we write specifications for everything. Every single part of the building project.

So in my time I have written a lot specifications; in fact hundreds of them, with 1000s of clauses, and I have developed my technique. Whilst I am now more often than not supervising the development of specifications, as my role moves towards management, I do still like to keep my hand in and it’s this process I would like to share.


We use and are advocates of NBS. For me personally, my first experience of NBS was in or around 1990, but this was via University at the time. I was properly introduced to it in 1994 when I joined the Design Büro, and this was the preferred method of specification writing.

Initially it felt like a chore; all those clauses and guidance notes. Phew, it took some time to complete properly.

Within a couple of years however, I came to realise just how fundamentally important this suite of documents and subscription was for us. It regularly got me out of a tight situation by providing workmanship clauses the contractor must adhere to in order to complete the works in a satisfactory manner, and as intended by the manufacturer.

Collaborative Workflow

Firstly, Specification writing is a collaborative exercise within our work flow. The complex nature of production information means more than one individual is often involved in the specifications development. It’s likely that the team member looking at the windows will not be involved with the internal screens that falls within the same document.

L10 Windows/ Rooflights / Screens and louvres.

So the magic formula here is in the first instance, never delete anything. If you think it’s irrelevant, score it through. Whilst you may not see the need for fire resistance and the workmanship required for this, the team member producing louvres or screens might do, and if the clause is gone they only know it’s gone by referring to another blank document. Which isn’t going to happen.

Here is an example:

- Gap between back of frame and reveal: Completely fill with ______ .

Gone but not forgotten for the next team member to review.


Next up, we want our specifications to be read and we want the information to be easily obtainable. It’s not in anyone’s interests if we make it difficult, so I instill on all those whom write for me to colour code the specification. It makes the detail you have added stand out and for me that’s what is important.

Another example for you:

- Gap between back of frame and reveal: Completely fill with Intumescent expanding foam by Acme Building Products Tel 1234 123 1234 O.S.A.

Excellent, clear, concise and legible for use on site by the foreman, with all of the information he needs.

Manufacturers Input

Ok, so we also need some help from the manufacturer to write the specification. We need the manufacturers’ representatives and their specification; after all it’s their product and they know how it should perform and what needs to be clear in the specification.

Unfortunately it’s easy to be lazy here.

It is rare that I get a specification from a manufacturer’s representative that’s correct, job specific and exactly what I need.

The golden rule here is always start with a blank specification - resist the desire to cut and paste. “It is not your friend”, and you will lose relevant and pertinent data.

I can cite many examples of specifications pulled of website’s and delivered via representative’s that are adjusted to suit their own needs; incomplete and not specific as mentioned above and here is an example:

- Courses: Level and true to line.
- Faces, angles and features: Plumb.
- Permissible deviations:
- Position in plan of any point in relation to the specified building reference line and/ or point at the same level ± 10 mm.
- Straightness in any 5 m length ± 5 mm.
- Verticality up to 3 m height ± 10 mm.

I have known these tolerances to be adjusted by the manufacturer / agent which has the potential to detrimentally affect the end product.

By cutting and pasting you are accepting the adjustments made, which mostly derive from British Standards, and ultimately when the chips are down you are the one with the professional indemnity. You have no contractual recourse with the manufacturer / agent - the buck stops with you.

Contractors Discretion

Next to ‘contractors’ discretion’.

This pops up so many times during specification writing when you have asked for help externally or within the office. In my opinion it is perilous to do this. The contractors’ discretion rarely meets with your approval. Don’t be lazy, be specific and tell them what you want.

Document Management

At Design Buro, I introduced the BS1192 numbering system approximately 18 months ago. It is imperative that all of our specifications are numbered correctly and easily and quickly traceable.

You need to know what is WIP (work in progress), Tendered and Issued for Construction. I would urge anyone who is not following the basics of BS1192 to adopt this immediately, name each specification document uniquely and store them in accordance with your internal systems.

An example of our numbering system below.

DBC888-DB-Z1-GF-SP-A-F10 [P1.1]

[Project]-[Originator]-Zone]-[Level]-[File Type]-[Role]-[Number]-[Attributed meta data]

The meta data is important and without a collaborative data environment the meta data has to be added manually and exist within the file name for retrieval and traceability.

QA Check

The last and my final point here is the QA check.

I cannot emphasize enough, that when specifications are a collaboration of team members, ultimately someone must take responsibility for the specification. In my view there is only one person, this being the project lead. Specifications should always be checked and verified by the person who is responsible for delivery. Failure to spend a couple of hours on this will result in many hours of rework later, I can assure you!

And don’t forget to go back and delete all of the scored text. Whilst most of us use computers to view these documents, the man in the site cabin most likely has a bubblejet printer and relies on a paper copy. Imagine printing a 1000 pages of specification to find half the document scored out?!

Neil has also very kindly provided a copy of one of his specification documents for anyone who is interested in a closer look. Download here.

If you would like to contribute a similar post and share your expertise, drop us an email to

Neil Marshall Design Buro


About the Author: Neil Marshall is a Chartered Architectural Technologist and Director at the Design Buro. You can follow him on Twitter or check out the Design Buro's website.

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.