Code for Sustainable Homes

CODE FOR SUSTAINABLE HOMES CERTIFICATE OF COMPLIANCE
A Code for Sustainable Homes Certificate of Compliance is a requirement in more and more planning permissions for dwellings. This page explains the Code, and how it affects the build process and the resulting home. While the Code does add yet another layer of complexity (with all its attendant paperwork) to the self-build process, Eco-Rating aims to shoulder most of this burden, leaving the architect or designer to get on with the design and the Client to enjoy the benefits.


WHAT IS THE CODE FOR SUSTAINABLE HOMES?
“The Code” is a method of evaluating a new-build housing development scheme (of any size) against a set of standards for environmental sustainability. Both the design and the construction process are evaluated. It has a wide scope, covering energy, water conservation, construction waste, security, recycling facilities, sourcing and choice of materials, flood risk, ecological protection and many other issues.

The performance of the design in each issue is evaluated against standards laid out in the Code. The results for all the issues are then collated, giving a total which classifies the development in Levels from 1 to 6. Typically Level
3 or Level 4 is currently required for self-build projects.
A further slight complication is that for each Level there are some Code standards which are mandatory.

A Code assessment is a rigorous process which requires collection of documentary evidence to support the evaluation of each issue. Most of this evidence is obtained from the drawings and specifications. It follows that these documents will have to include features that the Code introduces. Because a Code Level indicates a quality standard which is rigorously applied, it is reasonable to expect an increased market value for the dwelling.

Assessments are conducted by individuals licensed by an accredited organisation called a “Code Service Provider”. There are many ways to achieve a given Code Level because the Code is a scoring method, which allows flexibility – it means that if you do well in some issues you can relax in others. With Building Regulations on the other hand it is simply a matter of complying.


HOW WILL IT AFFECT THE BUILD PROCESS?
Before granting planning permission (for either Outline or Full Planning), planners often require a “pre-assessment”, which confirms that the required Code Level is feasible and outlines how it may be achieved, along with constraints and opportunities. From the self-builder’s perspective, a useful output of this stage is a schedule of the design features to be included and the construction practices to be adopted. Eco-Rating produces this document after full discussion with the developer and/or designer. In the self-build situation it can be particularly valuable for the assessor to be in regular contact with the developer or designer, raising any issues that need to be dealt with urgently. Even if this stage does not have to be dovetailed into the planning process it must still be performed, to ensure that the required Code Level is obtained. “If you fail to plan you’re planning to fail,” as they say.

With the plan in place, the next stage is to collect the evidence. As well as the drawings and specifications already mentioned, copies of correspondence, invoices, web pages and other such documentation may be needed.

When all is in place the assessor will lodge the assessment with the Code Service Provider. After checking the information they issue an “Interim Certificate” giving the Code Level achieved at design stage. It is often one of the conditions on the planning permission that this Interim Certificate is obtained before construction can begin.

Eco-Rating recognises that self-builders may not be familiar with Code certification, and one of my special contributions in self-build projects is to work closely with the key players through these processes.

Construction practices adopted will affect the Code result. Typical recommendations for Level 3 would be:
• a working Site Waste Management Plan, and diversion of 50% of construction waste from landfill
• monitoring of site water consumption against benchmark
• procedures for dust suppression
• procedures for avoiding pollution to ground and surface waters
• sourcing of temporary site timber via schemes such as FSC or PEFC

In addition to the above, for Level 4 I would typically recommend Considerate Constructors certification. For higher levels there may be a need to source timber used in construction of the dwelling via FSC, PEFC or similar schemes.

During construction, documentation will be collected as evidence that the agreed Code features and construction practices are being implemented. At least one site visit will be conducted. If there are changes (as sometimes occur), these will be evaluated and a partial re-assessment will take place. The assessor lodges the post-construction stage assessment with the Code Service Provider, who will issue the Final Certificate. The Code Level attained will depend on the post-construction evidence provided, and is not necessarily the same as the design-stage Level. Note that sometimes the planning condition is worded such that variations at post-construction stage need the prior agreement of the planning authority – it is advisable to check this point. Also there is often a condition that the dwelling cannot be occupied until the Final Certificate is obtained.


HOW WILL IT AFFECT THE RESULTING DWELLING?
If the Client wants a sustainable home, achieving Level 3 will probably make little difference to the finished dwelling. Higher levels will have more effect. In the first place it is useful to discuss the choice of building materials and constructions, as these affect the Code result.

A SAP Assessment and EPC are required for Building Regulations Part L1A. SAP Assessors often specify a solution (insulation, ventilation and heating systems) that will only just pass L1A, but it will help the Code result if the solution is much better than the minimum required. The outcome will then also be a home which is more economical to run. Renewable energy systems are often recommended, especially for Level 4 and above.

Similarly sound insulation testing or Robust Details are required to meet Part E, but with attached dwellings it will help the Code result if the insulation is improved beyond the minimum required. Likewise the result will be a home better protected from neighbours’ noise.

The Code requires that attention is paid to flood risk from all sources, and often calculations must be performed and SUDS systems installed. Good design of the SUDS system will again help the Code result, as will carrying out a Flood Risk or Flood Consequence Assessment. These steps will provide a measure of resistance and resilience to flooding, which may prove invaluable, especially if rainfall intensities increase as is predicted.

Daylighting calculations can be carried out to quantify levels of natural light in the main rooms. If the results are good, not only will the Client be benefitting from the natural light, but the Code result will also be improved.

A Home User Guide – written in plain language for the dwelling, to encourage and enable its occupants to adopt a more sustainable lifestyle – will also (if it meets the requirements) improve the Code result. The Guide is a rich source of local information, especially useful if you’re new to the area.

Eco-Rating offers many of these additional services, and for the more specialised services I am developing a network of trusted suppliers who are geared up to work with self-builders.


For Level 5 and above an ecological survey and report, aimed at protecting existing features ofecological value and enhancing the ecological value of the site, will usually be necessary. It may sometimes be needed for lower levels, and in most cases will give a helpful boost to the Code result. The benefits of this exercise are mainly to the natural environment, although this in turn benefits us all. Those with interests in that direction will have the resulting enhancement to look forward to.


Generally a rainwater harvesting system will be recommended, to reduce the projected potable water consumption. Other recommended features, all ofwhich improve security or reduce running costs, are as follows:
• Secure By Design certification
• secure cycle storage facilities
• energy-efficient and water-efficient white goods
• smart meter

Although the Code can be regarded as an unwelcome additional burden on the self-builder, it can be seen that achieving Code certification brings with it many advantages. These include features which reduce running costs, enhance quality, improve health & wellbeing, improve security and reduce flood risk. It is therefore reasonable to expect an increased market value.

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