Views are being sought on the main tool that will be used to assess the energy performance of buildings under the Green Deal and other schemes to improve energy efficiency in the built environment.

Buildings are responsible for a third of the country's greenhouse gas emissions and there is a blizzard of initiatives to try and reduce their impact.

Among them, today alone, are a tool from the Carbon Trust to help employers motivate their employees to save energy, and another reminder of the 'head in the sand' attitude of IT managers towards using power management technology to reduce the impact of computer use.

There will always be the human factor. But the designed-in energy use of buildings is being tackled fundamentally by a new government consultation, launched yesterday, on improvements to the Standard Assessment Procedure (SAP).

This is reviewed every three years or so, and is used by assessors to calculate the energy and environmental performance of dwellings, both new and refurbished, and will underpin the delivery of a number of key climate change initiatives, including:

• the Building Regulations for England and the Devolved Administrations
• the 2013 Amendment to Part L of the Building Regulations for England
• HM Treasury’s Stamp Duty exemption for zero carbon homes
• benchmark ratings for Northern Ireland’s House Conditions Survey
• Energy Performance of Buildings Directive and Energy Performance Certificates
• the Code for Sustainable Homes
• Warm Front
• Local authority stock reporting
• the Green Deal
• the Energy Company Obligation (ECO)
• the Renewable Heat Incentive (RHI).

Getting it right is thus absolutely crucial.

Poor performing air source heat pumps

One of the chief problems, it seems, is with air source heat pumps.

Several models are severely underperforming, and are even being installed in place of gas heating, rather than electrical heating, which can actually result in increased carbon emissions and costs (electricity used for heating results in almost three times the carbon emissions of gas).

In particular there have been complaints about the NIBE exhaust air source heat pump.

35 tenants of a housing association in Milton Keynes have lodged formal complaints about these pumps, to the Housing Ombudsman, to BRE, which is the body responsible for managing SAP, and to the Microgeneration Certification Scheme, the body which approves renewable energy installers and technology.

Two particular models have been sold to housing associations up and down the country, but tenants are finding they are faced with higher than expected electricity bills because of the number of electric motors used by the models in real life circumstances, which were not accounted for in the laboratory test that determined their alleged efficiency.

The Bedfordshire Pilgrims Housing Association campaign's Facebook page has had over 10,000 hits since its launch.

Campaign leader Jaime Dickinson said: "The more I uncover the more it seems to be a cover up.

"Our main complaint is that we are connected to gas, and so converting to electric heating is crazy," he continued. "Another of our estates has also started a complaint."

The new SAP consultation document proposes reducing the default seasonal performance factors used for heat pumps, and being able to include actual monitored performance figures in the calculations.

This will go some way towards solving the problem, but Dickinson is proposing that these pumps should be removed from the approved list altogether, or reclassified.

Improved assessment of greenhouse gas emissions

The proposed new SAP rules also contain several changes intended to improve the calculation of the climate-warming impact of buildings' energy use.

The first amendment is to include other greenhouse gases besides carbon dioxide such as methane and nitrous oxide.

Also proposed is to include indirect upstream emission sources associated with the transportation of energy, not just within the UK but outside of it.

This will mean that for the first time leaks associated with the compression and leakage of liquefied natural gas (LNG), which are considerably higher than those for natural gas from the North Sea, will be taken into account.

Emissions associated with transportation of fuels will also be included.

There will also be a change to the time period over which the predicted emission factors are calculated, to make it more relevant for existing buildings, which account for the bulk of SAP assessments.

The tool will also take account of boiler efficiency test conditions expected to be introduced under the European eco-design regulations and the heat losses from storage combi boilers that have not been tested for hot water.

But a number of proposed changes on boiler controls did not make it to the draft amendments and have not been included.

The proposed new version also makes it possible to include local wind speeds in assessing energy loss and wind power generation, and includes a revised basis for calculating the solar radiation from horizontal values based on orientation and tilt angle (or roof pitch) of solar panels.

This will affect the way predicted returns from solar installations are worked out under the feed-in-tariffs and the Renewable Heat Incentive, and is described in SAP technical paper STP11/SR01.

The SAP 2012 document is backed up by a number of technical papers and comments should be returned by 28 March 2012.

The gaps in SAP

There are many more factors which could be addressed in this round of changes to the SAP which would save even more energy.

Unfortunately, these are being put off to the next round, to take place in 2015, and they make a long list:

• Overheating and space cooling
• Use of solar panels for space heating
• Different types of low energy lighting
• Assumptions about heating patterns and internal temperatures (using evidence from the English Housing Survey’s energy follow-up survey).
• Introduction of a community heating database
• Low temperature circulation to heat emitters in domestic heating systems
• A review of the treatment of heating controls
• A review of different types of ventilation systems
• In-use factors applied to individual technologies
• Annual performance method for micro-CHP devices that provide hot water services only
• A review of occupancy factors.

Critics will be asking why, since the Green Deal is to be launched this year, more of these factors are not being addressed now, as the result could be poorly-performing solutions being 'locked in' to buildings for many years.