This is a detailed house-buyers / renters guide to reading an energy performance certificate (EPC). It covers what you should look for and what it all means. This first part, of two, looks at some first impressions, and how to read page one.

Why is it important to me?

People are sometimes surprised how much difference a good EPC rating can make to your household bills.  Although not every bill is reflected in the EPC rating (which only looks at the home’s energy costs), for many people the majority of their monthly bills are for providing heating, hot water and electricity for lighting – exactly the costs which the EPC rates on an A to G scale.

In a brand new home (where the EPC rating could be as high as B) the heating costs will be low and other bills will usually dominate, but this isn’t normally the case for an older home.  In a home with an EPC rating of perhaps F or G, the heating bills will be the biggest drain on your monthly budget, unless you choose to accept lower levels of comfort (cooler temperatures, shorter heating times); and who doesn’t want to be comfortable in their new home? 

The EPC will tell you whether you will be able to live comfortably, or have to settle for wearing woolly jumpers indoors to bring your fuel bills down.

If you don’t ask, you often don’t get!

Whether you are thinking of buying or renting, you should be offered the EPC whenever you are given information about a property you are considering.  Information clearly includes the property brochure, but it could also mean the online information you see on a property portal like Rightmove, or an agent’s own website.  If you are not offered the EPC at this point, make sure you ask for it.  

A common reason why agents don’t comply with the law is that buyers / renters don’t ask to see it, and so it’s left until the solicitor insists on seeing it as part of the legal stuff.  By this time, it’s rather too late for the buyer to make any decisions based on the information it contains! 

For renters, as a solicitor isn’t normally involved in the transaction, the EPC is often never provided.  Since the private rental sector is becoming the main housing source for today’s under-40s (nearly 4 million homes), this represents a lot of people not being given the information they are entitled to.

What does page one of the EPC tell us?

The two most important things on page one are the rating graphic and the table of fuel costs.  Taking them in turn:

The rating graphic – This is the headline message provided on page 1 of the certificate.  Currently there are two colour coded graphics, one in red/green and one blue/grey.  The second, blue/grey, graphic will be dropped next year so I’ll not consider it further here.  

The red/green graphic rates the home’s energy efficiency – that is, how much of what you pay for (heat, light, etc) do you get per pound spent on energy bills. This calculation is done per square metre of floor area, so that different sized homes are rated on an equal footing. Otherwise, a smaller but less efficient home might rate more highly than a larger, more efficient one, purely because it has less space to heat.

The graphic has two arrows – one indicating the home’s performance now, and the second showing the home’s potential rating if the most cost-effective recommended measures are all installed.  This potential rating is very important – it tells you if the home is capable of being improved at a reasonable cost, and how much better it could be after improvement.  

The arrows are both numbered with the SAP rating, before and after improvement; SAP is just the technical name for the method used to assess the home’s energy performance. 

It’s the difference between these two numbers, rather than the difference in the rating bands, which tells you just how much the home can be improved.  If the rating is low (say, E, F or G) and the potential is also low (say, an improvement of no more than 10 SAP points) and you want to be warm at reasonable cost, then this home is probably not for you.

The estimated energy use, CO2 emissions and fuel costs

Page one also provides a table (see above) that isn’t explained at all well.  This table will be replaced next year, but for now, it’s best to ignore the first two rows (energy use, CO2 emissions) and concentrate on the last three rows, indicating the home’s energy costs; these estimates reflect the floor area of the home, so for two homes with the same EPC rating, this table will show higher costs for the larger home.

The table gives estimates for heating, lighting and hot water, and the second column shows how much these costs could be reduced if the recommended improvements were made. Just like the rating graphic, it’s only the cost effective recommendations that are taken into account here, so the most expensive recommendations are ignored. If you have a large budget and decide to include the most expensive recommendations, the savings should be larger than estimated in this table.

If you have limited funds for home improvements, it makes sense to work on the item that has the biggest cost saving potential.  This is often, but not always, the heating, but in well insulated homes, lighting or hot water can be worth tackling first.

It’s worth knowing that these costs are averages for different households, based on an assumption that the home is heated for 9 hours each weekday and 16 hours a day at the weekend, with the main living area heated to 21°C and the remainder of the home to 18°C. 

Your heating preferences may be different, in which case the actual heating savings will also differ, and could be either higher or lower – if you use more, you will save more. The hot water and lighting estimates are based on the size of the home: for example, it’s assumed that a four bedroom home will be occupied by at least 4 people, and a one bed flat will have 1 or at most 2 people living there.  If the four bed home only has one occupant, their lighting and hot water use is likely to be less than the EPC estimate.

As a prospective buyer or tenant, you won’t have personally seen the DEA at work, and you have to trust that (s)he did a thorough job of inspecting the property.  However, you don’t have to accept an inaccurate EPC. If you have reason to think that an error has been made you can challenge the DEA, whose accreditation details are given on the EPC.

The rest of the EPC

I’ll consider the meaning of the rest of the EPC in my next blog, and give some ideas of how to use the information it contains.

About the author: @linniR is a consultant, a freelance writer and a Domestic Energy Assessor accredited with the NHER scheme, and she enjoys all three.  She tweets regularly on issues relating to energy efficiency and renewables and provides consultancy, especially in relation to training needs.

If you have a question about anything in the above blog, please ask it in the comments section below.