Energy, Sustainability and Carbon – Page 2

Part O overheating: simplified method or modelling

Approved Document O offers tabulated glazing limits or a dynamic thermal simulation. Single aspect flats, high risk locations and noisy roads push schemes into the modelling route whether the team planned for it or not.

Be Green: sizing renewables on a constrained roof

Be Green stands or falls on the roof plan. Gross roof area overstates the array by a wide margin once plant, greening, access, edge setbacks and inter-row spacing are deducted.

The Be Clean stage: heat networks and connection evidence

Be Clean is the only stage of the energy hierarchy that depends on a third party replying. Authorities now expect the enquiry correspondence, not an assertion.

Part L 2021 notional building and what it means for design

Part L builds a hypothetical dwelling with your geometry and a set specification, then makes its results your target. The fabric target is the one you cannot buy.

Green roofs, biodiversity and the energy trade off

Three policies claim the same roof. Stacking functions in a biosolar or blue-green build-up resolves most of it, and an allocation drawing settles the rest.

Energy evidence for agricultural and equestrian buildings

An unheated barn does not need a dwelling calculation. The exemption that applies, how it treats stables, and the proportionate submission that answers local policy.

As built Part L evidence to discharge an energy condition

An energy condition is discharged with evidence that can only exist once the house is finished. Collect it as you build, and allow three months before occupation.

Combustion plant in new development: policy resistance

Air quality, carbon targets and heating hierarchies all push against on-site combustion. What the evidence base has to show if the plant is to survive consultation.

Be Seen reporting and post occupancy energy monitoring

Post occupancy energy reporting is a five year commitment that starts with the meter schedule. Get the metering wrong at design stage and the data cannot be produced.

Pre-demolition audits and honest reuse targets

A pre-demolition audit is a quantified inventory, not a statement of intent. Here is what it records and how to set targets you can still stand behind at completion.

Mixed use energy statements: two compliance routes

Residential and non-residential floorspace are modelled under different volumes of Approved Document L. Here is how to keep one energy strategy honest about both.

Energy, Sustainability and Carbon6 min read

The arithmetic behind a regulated carbon reduction figure

A regulated carbon percentage compares a notional building baseline with your modelled proposal. Which emissions count, how to report stage by stage, and what an assessor rechecks.

Fabric or technology: value engineering after permission

Swapping glazing or cutting a solar array after permission can breach the condition tied to the approved energy statement. The recalculation, the routes and the timing.

Energy requirements for a Class MA conversion

A Class MA prior approval cannot consider energy performance. The duties arise under the Building Regulations on a material change of use, and overheating in deep floorplates is the real risk.

Substructure and basements in whole life carbon

Piles, retaining walls, slabs and spoil haulage are concrete, steel and diesel. Leave them out and a basement scheme looks identical to one without a basement.

Carbon factors in SAP and what electrification changed

The grid electricity factor in SAP fell by about three quarters between SAP 2012 and SAP 10 while gas barely moved. Every carbon claim in an energy statement depends on which set was used.

15 October 2026Read article →

Deep retrofit of a solid wall terrace: the planning issues

Cladding a house falls outside permitted development on article 2(3) land, and an Article 4 direction can remove the right elsewhere. The harder problems are the party line and the pavement.

Fabric efficiency against the carbon target in an energy statement

Fabric energy efficiency measures demand alone, so renewables and low carbon heat do nothing for it. Form factor, glazing ratio and junction detailing decide the result.

Passivhaus certification against local plan energy policy

Certification measures energy demand per square metre of treated floor area. Policy measures carbon reduction against a notional building. Submit both and translate between them.

Net zero carbon policies in local plans and the offset payment

A net zero carbon policy means a defined on-site reduction plus a cash payment for the residual tonnes over 30 years. Price both before the land deal, not at section 106 stage.

Energy, Sustainability and Carbon6 min read

Overheating: Approved Document O against CIBSE TM59

Approved Document O and TM59 answer different questions with different criteria. A scheme can pass one and fail the other, and officers increasingly ask for both.

Energy, Sustainability and Carbon6 min read

SAP 10 carbon factors and the heat pump case

The revised electricity emission factor changed the arithmetic of every energy statement. A heating strategy that failed on carbon under the old figure can pass under the new one.

Future Homes Standard: what it changes for a small scheme

The Future Homes Standard is a Building Regulations change, not a planning one. For a small scheme it lands on the heating system, the fabric and your dates.

Discharging a renewable energy condition after completion

A renewable energy condition is discharged with commissioning evidence, not a promise. Here is what each wording needs and how to sequence it before occupation.