Good practice guidance has become available, and risk management tools have been developed to help housing organisations to identify and mitigate risks, and to ensure that their fuel-saving programmes deliver quality work. It is important that housing organisations understand and manage risks, because the consequences of not doing so are serious, including:

• poor energy performance (i.e. fuel cost savings significantly less than predicted, leaving residents with high fuel bills)

• condensation, mould growth and the deterioration of finishes, fabric and structure

• overheating in warm weather

• diminished resident satisfaction (and increased complaints)

• erosion of asset value and resources

• loss of reputation and undermining the commitment to fuel-saving

In order to manage risks it is first necessary to understand the fuel-saving improvement process, then to introduce risk mitigation techniques based on documented good practice standards and procedures.

The reason why the omission of the design stage of the process is critical is that the three places where improvements often fail are all places where design input, attention to detail with drawings, is critical. They are:

• at the corners, junctions and edges where building elements meet, and around openings, where continuity of insulation and of the air barrier are critical to minimising thermal bridging and to eliminating air infiltration and air leakage

• at the interfaces between the building fabric and the building services, where heating and ventilation systems and their controls must be matched to heat loss and air permeability

• at the interfaces between systems and people, where commissioning, handover, control, and maintenance are critical to achieving the intended performance

This is also the reason why PAS 2030 is not fit for purpose, and should not be relied on by housing organisation as an assurance of quality. PAS 2030 specifies that installers should be certified according to measure-specific training schemes established by industry before the importance of whole-house improvement was recognised. Its focus is on improving individual elements of the dwelling by installing individual measures, but not on the junctions between them; and on installing systems correctly, but not on the interfaces between those systems and the building fabric or the people who will use and maintain them. PAS 2030 includes a separate annex specifying training and certification requirements for the installation of each individual measure or system, but has almost nothing to say about the corners, junctions, edges and interfaces that are the places where problems occur. Thus it preserves the fragmentation of the industry rather than promoting a robust, integrated approach.

These procedures include assessing dwellings, consulting residents, designing and specifying improvements, engaging contractors via framework contracts and inspecting work to check compliance with designs and specifications. Housing organisations should build on this valuable experience when venturing into energy efficiency improvements.

A robust process for medium- and large-scale fuel-saving programmes is shown in Figure 6.2.

These are based on experience and good practice guidance, and because delivering improvements is a learning process they are subject to change, under the control of the Quality Manager. There is considerable scope for housing organisations to share their fuel-saving improvement libraries with each other, possibly via the NHMF, or to develop them collaboratively through common procurement processes. There is also scope for framework contractors to contribute to them. However, it should be noted that many designs and procedures may be stock-specific.

• Ensuring that dwellings are properly assessed prior to measures being designed, specified and installed. The assessment process should be more than a simple SAP energy rating assessment carried out by a Domestic Energy Assessor: it should embrace all relevant aspects of the dwelling, including its current performance, its construction type and state of repair, planning constraints, design constraints, cost considerations and a technical risk assessment. Specialist assessors should be deployed to ‘vulnerable’ dwellings (i.e. those built before 1920, which may have vapour permeable construction) and to dwellings where the installation of high-risk measures (e.g. solid wall insulation, communal heating or whole house mechanical ventilation with heat recovery) is anticipated.

• Maintaining the library of materials, products, construction details and procedures. inevitably, the library will continually change as the scope of the improvement programme develops, and in the light of experience. There should be rapid feed-back from inspections and from monitoring and evaluation work to ensure that elements that prove problematic are quickly improved or replaced, before further defective installations are completed. Updates should be subject to a strict change management procedure and communicated clearly to users (i.e. assessors, designers, specifiers and installers).

• Operating an inspection process, involving inspections of work both during and after the installation of measures. Inspections are expensive, and there is unlikely to be sufficient resource to inspect the installation of every measure in every dwelling. Technical risk assessments should therefore be used to target inspection resources on the highest risks, i.e. where problems are most likely to occur, with the greatest impact. Elsewhere, good quality improvement work will rely on well-trained site supervisors.Operating a sample monitoring regime, involving both basic energy performance monitoring and simple post occupancy evaluation (i.e. proforma interviews with residents) to ensure that the fuel saving programme delivers what residents are promised. More elaborate and expensive energy performance monitoring, post construction reviews and detailed post occupancy evaluation may be appropriate in some cases, especially where complex or high-risk whole-dwelling fuel saving imrpovement has been carried out. The monitoring regime is critical to the continuous improvement of the overall retrofit process.

• Finally, collaborating with housing managers to investigate residents’ complaints, rectify problems and feed experience back to the library.

• Identify appropriate improvement measures to suit the residents, the buildings and the local contexts. Spend time understanding residents’ constraints. Beware of over-optimistic performance predictions (especially if work will be funded by fuel cost savings and residents are currently under-heating their homes).

• When evaluating improvement options, adopt a "fabric-first" approach: first improve the insulation and air tightness of the building envelope, in order to reduce heat loss; then improve the building services, to increase efficiency; finally, add appropriate renewable energy systems to "top-up" performance to the required standard.

• Establish an air-tightness and ventilation strategy to ensure good internal air quality, control moisture and reduce the risk of condensation and mould growth. Recognise that in most dwellings deliberate ventilation will need to be improved if insulation is added or the dwelling is made more air-tight.

• Specify the materials and products to be used. Design the construction details at all junctions, corners and edges of building elements. Maintain the integrity of the insulated envelope and the continuity of the air-barrier.

• Match the type and capacity of heating and ventilation systems to the reduced heat loss and air permeability respectively. Keep controls as simple as possible, and readily accessible.

• Ensure that ventilation systems include provision for fresh air inlet as well as for stale air extraction. Recognise that mechanical ventilation with heat recovery (MVHR) will not work effectively if the air permeability of the building envelope is more than 3 m³/m²hr @ 50 Pa. MVHR is also very difficult to install properly in existing buildings. Ensure access is provided for filter cleaning or replacement.

• Incorporate measures to reduce overheating, including external shading, reduction of internal gains (by installing very energy efficient lamps and appliances) and provision for secure night-time ventilation in summer. Ensure that any ventilation system with heat recovery includes summer by-pass of the heat exchanger.

• Avoid using separate installers for each improvement measure: use multi-skilled installation teams or require installers to cooperate. Ensure that installers are properly briefed by means of "toolbox talks" – especially about air tightness.

• Procure the design, not a contractor’s or installer’s interpretation of it. Implement change management control to eliminate inappropriate substitutions of materials or products. Do not allow installer design unless it is pre-documented and approved by the designer.

• Undertake pre-completion testing (pressure testing and thermography); target sample testing and inspections using risk assessments. Provide rapid feedback to facilitate remedial work, and improvements in designs and specifications.

• Commission all building systems together at the same time, not separately, in accordance with a pre-agreed process, and obtain commissioning certificates.

• Adopt a robust handover process: explain what has been installed and how to use it by means of verbal briefings, supplemented by graphic instructions and follow-up visits by trained resident advisors.

• Provide residents with advice about the use of controls. Explain how risks of condensation and of overheating can be managed. Explain the consequences of disabling ventilation systems. Promote behaviour that will reduce fuel costs.

• Brief the maintenance team, providing comprehensive descriptions of the systems, components, controls and service requirements: they are as important as the residents!

• Undertake post-construction reviews, post occupancy evaluation and monitoring to confirm performance, internal air quality and user acceptability. Target monitoring using risk assessments and focus on the highest risks. Provide rapid feedback to the quality assurance team so that materials, products, details and processes can be improved.