Energy Performance Certificates – What Does an Assessor do in Your House?

EPC Bromley

You know what an Energy Performance Certificate (EPC) is, but what exactly does an assessor do when they visit your house?  If you call EPC Bromley to arrange an domestic energy assessment then what can you expect when they visit?

Have a look below for a summary of the items that EPC Bromley will consider during the assessment for your EPC.

House Age and Build Type

Working out the year that the house and any extensions were built will tell us what the building regulations were at that time and therefore how energy efficient the house is in general.  A house built in 1930 would have had no insulation fitted to the walls as a regulation, this is not the case with a house built in 2010.

The build type (detached, terrace, flat) tells us where the heat may be escaping from.  A detached house generally has at least four cold walls whereas a semi will have one shared wall which is warm.  A flat could be heated from all sides and have a communal corridor area which is heated too.


Quite simply we measure the volume of your property.  We need to know the amount of space you have to heat before we make a judgement on how you heat it.  We’ll also consider whether you have a conservatory. 

If your conservatory has an outside door sealing it off then it is discounted, if it is open plan then it is included and considered a source where heat can escape more easily.


Wall types are generally solid, cavity or timber framed and are as efficient as the regulations in place when they were built.  Traditionally, solid walls without insulation were used on houses until well into the 1930s, this kind of wall is very inefficient. 

If it is a cavity wall then we check whether the cavity has been filled with insulation retrospectively, as originally cavity walls were not filled.


We poke our head into the loft and see whether it is insulated, if it has then how deep is it?  Traditional insulation at the joists should be at least 270 mm deep.  Remember, if you crush it down with floorboards to 100 mm then it is only 100 mm effective.


Are they solid or suspended floorboards, has it been insulated or do you have another dwelling below you?


We consider how many doors you have and whether those doors are insulated.  We look at how much glazing you have and whether it is single, double or triple glazed.  If it’s double glazed we consider what year it was installed, double glazing installed from 2002 onwards is much more efficient than glazing fitted before then.

If it was fitted before 2002 then we consider the frame type (metal, pic or wood) and the gap between the panes of glass.

We also look at how much draught proofing is in place.

Ventilation & Lighting

We look at how many fireplaces the property has and whether these are open, we also look for any mechanical ventilation or cooling systems that are in place.

We count the amount of light fittings and at the same time we count how many of these have low energy bulbs in place.

Heating Systems

How do you heat your home?  If you use a traditional boiler then we consider how efficient that boiler is.  Modern condensing boilers get the highest efficiency scores.

We consider how the heat is distributed (radiators, underfloor) and how that heat is controlled.  Properties that have a room thermostat, thermostatic radiator valves and a heating timer will score  highest.

If your property has more than one heating system then this is also considered as well as any secondary heaters such as a gas or electric fires in the reception rooms.


How do you heat your water?  Do you have a combination boiler or a hot water cylinder?  If it’s a cylinder then how large is it?  Is it insulated?  Does it have a thermostat?  We then consider how many bath/shower rooms are in the property, how many of these have baths, showers or both?

We also look at other options for water heating which may be in place.  These include solar water heating, waster water heat recovery systems (WWHRS) and flue gas heat recovery systems (FGHRS).

New Technologies

We investigate if you have any other new technologies in place like solar photovoltaic panels or a wind turbine.  The terrain you live in is considered(urban, suburban, rural) which determines whether a wind turbine would be suitable.

Checks are made at this point to see what type of electricity meter the property is has (dual or single charge).   If the house isn’t heated by a gas boiler, we see whether there is a gas meter indicating it would be an option.

Any other info

Here’s where you can note whether the property has a swimming pool or  uses a more obscure way to heat itself.  For example micro CHP or a biofuel that isn’t listed in the usual database.

If you don’t understand some of these points, feel free to get in touch with EPC Bromley and ask.  Otherwise your EPC Bromley assessor will be happy to answer any questions you may have whilst the survey is taking place.

Double Glazing Effectiveness and Alternatives

EPC Bromley

We all know that double glazing is more efficient at keeping the heat in your home and the cold out than single glazing can ever be.  It is also completely obvious that triple glazing is more energy efficient than double glazing.  But did you know not all double glazing is created equal?  EPC Bromley advises the very basic differences between double glazing and what alternatives there are.

Double Glazing Types

The types of double glazing and their rating on an energy performance certificate are broken down into two basic types.  Double glazing installed at any time up to 2001 and double glazing installed in 2002 and after.

The latter is considered the most energy efficient as regulations surrounding the manufacture of double glazing changed at this time.

If your double glazing was fitted in 2001 or earlier then we need to ask a couple of questions before establishing how efficient it is.  The first question is ‘Is it a PVC frame?’.

If it isn’t a PVC frame and is made from wood or metal then it is considered the least energy efficient. 

If it is PVC then we need to establish how big the gap is between the pieces of glass.  Is it 6 mm, 12 mm or more than 16 mm?  The bigger the gap the more energy efficient the glazing is considered.

Double Glazing Alternatives

EPC Bromley realises that double glazing is not always affordable, appropriate or even allowed on certain properties.

Depending on the size of the property, double glazing can cost anything between £3,000 and £10,000, with costs for ultra efficient triple glazing even higher.  This is beyond a lot of people’s means, though EPC Bromley does recommend considering how much you will save on your heating bills each year if you were to have it installed.

There are other reasons for not getting double glazing.  The house might be in a conservation area, it might be a listed or period building, or in some cases it might just be opposite or near a listed or period building.  In these cases you’ll need to look for alternatives.

Secondary Glazing

This is a secondary pane of glass, which is fitted in the window reveal behind the existing pane of glass.  It’s not as well sealed as a fitted double glazing unit but it is a huge amount cheaper and will save you money.  It is even more cost effective if you fit it yourself, it’s an easy job that is achievable by even the least confident DIYers.

EPC Bromley can also reveal that secondary glazing is considered just as effective as pre 2002 double glazing on an energy assessment.

Curtains, Blinds, Shutters

Heavy curtains can be a very cheap and effective way to reduce your heating bills.  Heat loss will be reduced and draughts can be blocked out enabling you to feel the benefit immediately.  Purchasing draught excluders for draughty doors is a must too.

Blinds fitted in a frame can provide a complete seal, as can shutters, these have the added advantage in that they look attractive and take up less space than curtains.  They are also easier and cheaper to keep clean.

Hot House Howlers – Turning Down the Heat At Home

EPC Bromley

A recent government survey suggests that we are heating our homes to a far greater temperature than we have in the past.  It suggested that the average home was up to four degrees centigrade hotter than it was in the early seventies.  This is something that EPC Bromley has also noticed during domestic energy surveys in Bromley.

The total energy we as a nation consume is falling, but the energy that is being consumed in people’s homes is up by over 30%.  The fact that there are approximately eight million more homes than there were in 1970 does play a part, but our heating habits also have to shoulder a large part of the blame.

An issue with these figures is using averages means that people at the extreme end of energy usage are ignored, despite being the main part of the problem.  My father-in-law, for example, sets his home thermostat on 27°C and has the timer set on 24/7.  When we visit we spend the time turning the thermostat down, opening windows and switching off radiators.

It’s people at this end of the spectrum who make us forget about people at the other, those in fuel poverty who struggle to heat their homes at all.

It may be true that on the coldest days of the year, a tweak upwards of a few degrees on the thermostat will actually make a difference.  But it’s forgetting to turn the thermostat back down again after the temperature rises to something we can bear, that’s where the problem lies.  It is imperative that our homes have the right set up when it comes to heating controls.


In a traditionally heated home with a gas boiler, EPC Bromley recommends that you have the following in place in order to have effective control of your heating.  If you have all of these in place you will achieve the highest score on your energy performance certificate.

  • A room thermostat
  • A timer (for heating and hot water)
  • Thermostatic Radiator Valves (TRVs)


There are also a range of technological breakthroughs for the tech savvy.  These include smartphone apps with which you can accurately set timings and temperatures for your heating system.  Some even make use of GPS to ensure that the heating switches on and off as you leave and return to the house. 

Some of these apps are actually being introduced by the energy companies themselves.

Our obsession with modern technology may in fact end up being the solution to our energy usage at home, but it’s worth remembering that these apps are far more effective for owners of large detached houses, than they are for people in smaller properties and flats. 

In the case of the latter, something as simple as effective draught proofing may prove cheaper and more efficient in the opinion of EPC Bromley.

Draught Proofing Recommendations

EPC Bromley

Whether you’re looking to make improvements before you have your EPC done, or are following the recommendations after getting it done, these improvements always seem to be a little expensive.  At EPC Bromley we feel that this needn’t be the case.

The improvements that are going to have to greatest effect on your energy efficiency rating are things such as a new boiler (up to and sometimes over £1,000); solid wall insulation (£4,000-£10,000, depending on the size of your property); and Solar PV (around £6,000 – £9,000).

These aren’t exactly cheap but each one will give you a significant improvement on your energy efficiency.  You might even be considering the dreaded but often weirdly recommended solid floor insulation.  A massive expense, a huge upheaval but for very little reward, why it’s constantly recommended is anyone’s guess?  The recommendation from EPC Bromley is not to bother with this.

The cheapest and one of the most effective ways to make your home more energy efficient is draught proofing.  Remember, there are two considerations when you are trying to make your house warmer.  Firstly, what it says on paper, secondly, what makes it feel warmer.  Draught proofing definitely fits into the second category, especially on houses built in 1939 or before.

Where do you need to draught proof?

  • Doors and Windows  – The edges are the most obvious places but don’t forget about letterboxes and keyholes.  If you aren’t able to install double glazing or can’t afford to, then remember that secondary glazing can be just as effective.
  • Suspended floorboards – Most houses pre 1930s will be built on suspended floorboards.  Make sure the gaps are sealed in between the floorboards, check whether there are any gaps between skirting and floor.
  • Chimneys – If you have a chimney that is not in use then ensure that it is sealed up properly.  Ensure there are no gaps.
  • Pipework and electrics – Sometimes holes have been drilled through walls to allow pipes or cables through.  Ensure that all of these holes are filled in and that no warm air can escape.
  • Loft hatch – An often forgotten part to insulate when loft insulation is done as a DIY project.  Don’t only insulate the loft hatch, but ensure that the edges are also protected.

What does EPC Bromley recommend when it comes to draught proofing?

Although draught proofing can be done relatively cheaply, it is still important to make sure you use an effective product in every area.

Remember that window frames and floor boards made of wood will expand and contract as they heat and cool every day, so a material that can tolerate this movement is important.  Wooden frames can sometimes warp too, leaving irregular gaps to fill, a product that can fill these gaps is important to consider as well.

Why is draught proofing important?

Warm air is attracted to cold air, if there is a gap to the outside then warm air will be sucked out of it, meaning your heating will have to work even harder to warm your home to the temperature you desire.  Not only is this energy consumption bad for the environment, it’s also costing you money.

EPC Bromley recommends popping down your local DIY shop and investing small for a potentially larger gain.

Top Ten Tips for Better Home Energy Efficiency in Bromley

EPC Bromley

Read below for the top ten tips for energy efficiency in your home from EPC Bromley.

  1. Replace light bulbs with LEDs – Gone are the days when energy efficient light bulbs made your light fittings look ugly and were as bright as a flickering candle.  Modern LED spotlights, for example, are now bright enough  to replace your halogens and they come in all shapes and sizes to fit any light fitting.
  1. Control your heating – Your heating and hot water take up over half of your monthly fuel bills.  Ensuring you have a heating programmer, a room thermostat and thermostatic radiator valves and using them effectively could save you a ton of money each year.
  1. Draught proofing – Unless you have a particularly modern home you will be losing heat through gaps around doors and windows, or through the floorboards or chimney.  DIY draught proofing can prove to be incredibly cheap.
  1. Insulate your hot water tank – Your tank should have highly efficient foam insulation fitted around it.  If it doesn’t, then purchase a hot water cylinder jacket.  It’s far less efficient but better than nothing!
  1. Wall insulation – Cavity wall insulation is efficient and cheap (sometimes free!).  If you need solid wall insulation then it is far more expensive, but will save you hundreds of pounds in heating bills each year.
  1. Ensure you have double glazing – Double glazing fitted after 2002 is far more efficient than before.  If you are unable to install double glazing then secondary glazing can be just as effective.
  1. Loft insulation – Very important, if you have no loft insulation at all then this will seriously affect the energy efficiency of your house.  Remember, the recommended minimum depth is 270 mm.  If you place floorboards over the top of insulation it is only as effective as the depth it is squashed to.
  1. Use your shower rather than a bath – Showers use far less water than a bath, therefore your boiler is working less time to heat the water.
  1. Install solar energy – Solar thermal panels for hot water and Solar PV panels for electricity will not only make your home more energy efficient, but they will also save you a lot of money.  If you live in a rural area it is also worth considering a wind turbine.
  1. Track your energy usage – Energy monitors help you to keep an eye on how much energy you are using.  Most energy providers will be able to supply you with one.

If you need any other advice regarding domestic energy efficiency, call EPC Bromley to speak to an expert.