Consequential improvements in construction
Consequential improvements refer to energy efficiency improvements required by regulation 28 of the Building Regulations, guidance for which appears in Section 6 of Approved document L2B: Conservation of fuel and power in existing buildings other than dwellings.
- An extension.
- Installation of new fixed building services (other than renewable energy generators).
- Increasing the capacity of fixed building services (other than renewable energy generators).
.... (to the) extent that such improvements are technically, functionally and economically feasible.
In most circumstances, this means that the payback period for the consequential improvements required does not exceed 15 years (or less if the expected life of the building is less than 15 years).
Consequential improvements could include:
- Upgrading heating, cooling or air handling systems.
- Upgrading lighting systems.
- Installing energy metering.
- Upgrading thermal elements.
- Replacing windows.
- On-site energy generation.
- Applying measures proposed in a recommendations report accompanying an Energy Performance Certificate.
In the case of changes to fixed building services, the building fabric should be improved so that the energy consumption of the services is not excessive, and additional consequential improvements must be made as described in the list above. Improvements to the building fabric in this case do not count towards the value of the consequential improvements. NB This does not apply if the services capacity is increased to supply a new extension rather than to improve services to an exiting space.
For changes to fixed building services, improvements to the building fabric are considered technically, functionally and economically feasible where the existing thermal elements have a U-value lower than those set out in the approved document. In the case of cooling, both the U-values of thermal elements and the solar gains of windows are set out, and in the case of lighting, an effective lamp efficacy is set.
Once the works are complete, the building owner should be provided with sufficient information to operate the building efficiently. This can be done by preparing a building log book.
NB Proposals to extend requirements for consequential improvements to dwellings (as part of the introduction of the green deal) were finally dropped by Communities Secretary Eric Pickles at the end of 2012.
 Related articles on Designing Buildings Wiki
- Building log book.
- Building Regulations.
- Energy performance certificates.
- Energy targets.
- Environmental plan.
- Green Deal.
 External references
- Approved document L2B: Conservation of fuel and power in existing buildings other than dwellings.
Featured articles and news
Sadiq Khan publishes a new development strategy for the capital.
In the week of the momentous Heathrow decision, we look back at the development and design of T5.
BSRIA’s flagship event will address performance and wellbeing beyond compliance.
Young Architects and Developers Alliance launched to build the relationship between the two disciplines.
BS 8536-2:2016 Design and construction: Code of practice for asset management (Linear and geographical infrastructure).
Paying for off-site goods or materials can be useful, but it puts the client at risk.
People power can be transformative if properly informed and inspired.
ZHA win competition to build an Urban Heritage Administration Centre in Saudi Arabia.
Leaps, not steps, are needed to avoid a ticking time bomb, say BRE in response to Farmer Review.
A multi-purpose hall in France covered in a translucent orange membrane.
Winning designs revealed for a rock formation-influenced residential complex in Rennes.
An article explaining the techniques, regulations and environmental impacts of carbon capture and storage.
Watch one of the first documentaries by the acclaimed Adam Curtis, examining the substandard system building of the 1960s.