Derwenthorpe resident Catherine Jardine asked Studio Partington -(who designed our houses) for advice about controlling summer heat. We start with some tips on how to use what you’ve got, and then there’s some advice about external shades that you can add. And if you want to learn more, there’s a guide from the NHBC, also written by Partington Studios.
Keeping your house cool
Good ventilation is … key. … Get cool air circulating through the house in the early morning and late evening and then close everything down once the external temperature [is above] the internal temperature (this is second nature in a Mediterranean climate, but not so in Yorkshire!).
The worst time is usually mid to late afternoon, when … heat is coming into the home directly from the sun and when the [air] temperature outside is also high, ….
So when it’s going to be a hot day (over, say, 19 degrees), keep your doors, windows, and blinds closed during the heat of the day to stop the house getting too hot: you can’t cool a house down with warm air, even if it is breezy. In the evening, when it’s cooled down again, open windows front and back to get the house cooled down again.
Check the windows and doors section of our house guide, to find out how to prop your windows open safely. Open them front and back, to allow cool air to flow through.
Some form of sunshading externally will certainly help prevent unwanted solar gains but there are some things to think about if a shading device is retrofitted. Firstly it is much easier to control south facing direct sunlight rather than east or west.
On a south side the sun is high and a structure projecting horizontally from above a window will shade the window by approximately the depth of the projection (sun being at 50 or so degrees height in June).
Low level east and west sun is much harder to control and is usually shaded with vertical fins or some kind of draw down external blind. Both of these are difficult (as is the traditional Mediterranean shutter) with the way we make windows in the UK, which are always outward opening to keep the rain out.
Note that close fitting internal blinds can also be effective, if you use them well.
I attach some examples of what can be done as a retro-fit. The … wall will need to support the load of the shade so there will often be struts or cables and fixings at several points back to the brick work.
As with most things the best solutions come from traditional simple to operate means such as shutters, which would work over non-opening windows, but there are more sophisticated and automated systems. The most innovative manufacturer is Renson, who do commercial and domestic shading systems.
The little guide we did a few years ago for NHBC (also attached) explains the problems we are starting too see in well insulated homes and although more of an issue in urban areas people are beginning to be concerned about rural schemes as well.
Global warming means we’re seeing longer, hotter summers. Air conditioning makes it worse: and is expensive to use, but shading and natural ventilation are free. So we hope this guide will be useful to you!
In 2019 Carey English set up a group for those interested in action for the prevention of global warming – a group which Nick Hall and Jean Lavers joined. It was a small group at first but nonetheless we planned and executed many events under the heading “Love Your Planet”. When Carey and Guy moved away at the end of 2019 we tried in vain to find a replacement as leader. Nick and Jean, called a meeting in January, deciding to promote the solar panels project in Derwenthorpe. Two other households had the same idea. We were convinced it was a good, long-term investment and a way of reducing our carbon emissions. As the Energy Saving Trust says:
Over the years Jean and Nick had sounded out Joseph Rowntree Housing Trust as to whether they were going to initiate a project to put solar panels on our roofs, let us keep some or all of the electricity generated, and sell surpluses to the grid. Our covenants on purchase of our houses allow them to do that. But by 2020 it was clear they weren’t going to. So, if we wanted solar panels, we would have to buy them ourselves. We decided to try. Making that decision felt good. Making a reality of it required much learning, much effort. It was a two-track process: (1) finding out if anyone else in Derwenthorpe was interested, and promoting the idea; and (2) was there anyone out there who we’d trust to clamber about on our roofs and put panels on, and get the wiring right and all the other equipment?
We formed a small working group: Jean Lavers, Nick Hall, Harriet Ennis, Chris Ennis, Richard Lane, Graham Smith and Ian Eiloart. We are non-expert Derwenthorpe residents except for Richard, who works in sustainable energy and kindly gave his time as a volunteer adviser. We got plenty of encouragement and useful advice from JRHT, particularly Joanne Lofthouse (Derwenthorpe Manager) and Owen Daggett (Sustainability Manager). Richard Partington and his colleagues, architects for Derwenthorpe, gave us both encouragement and very helpful technical advice.
1.Publicising the initiative
We began by designing a questionnaire, aimed at gauging what level of interest there might be in Derwenthorpe. How keen were residents to get (and pay for) this addition to their houses?
Then came lock-down. At that time (mid-March) no-one, we felt, would be interested. We went to sleep (got involved in other things) for a couple of months. Late April, though, the invitation came to put something into the newsletter “LotsOn in Lockdown”. Why not a 3-line item asking each reader what they thought of the idea? We got a couple of dozen positive responses.
We followed this up with an article on the DRA website, copied onto Facebook – this produced several more interested people – enough to know that we were going to get a group able to have a serious dialogue with suitable firms.
We also wanted to be sure that every household had the chance to consider the idea. We drew up a questionnaire, asking simply: do you want a no-obligation quote? Yes or No? Similar questions for a battery and whether the battery should be able to charge an electric vehicle. Thanks to some dedicated volunteers we got questionnaires to all the Derwenthorpe houses (some 450) by mid-July. About 20 new addresses came up as a result – 60 in all.
2. Choosing installer firms
The first concern (April/May 2020) was whether any firm was doing this kind of work, and could they do it under the various Covid-19 restrictions. And would they?
We obtained details of twelve firms from the relevant part of the Which? Trusted Trader list, plus two by recommendation from JRHT, who had used them on other projects. We wrote to them asking if they were interested and if there would be a discount on bulk purchase.
Our first check was whether or not they were listed under two quality control schemes: MCS and RECC.
MCS is the Microgeneration Certificate Scheme. MCS certifies low-carbon products and installations used to produce electricity and heat from renewable sources. Having an installation certified by MCS means that any surplus power generated is acceptable to the grid.
RECC lists firms who have signed up to the Renewable Energy Consumer Code, which governs things like technical site surveys, getting necessary permissions, contract documentation and customer care issues. https://www.recc.org.uk/scheme
We sent a Request for Information to five of the firms, selected from the original set as being listed under both MCS and RECC schemes and being not far away (the furthest being Leicester). From people we had heard from as being interested in the project we had 16 addresses whose residents were happy for the five firms to estimate, by desk-top survey, what a system would cost. (The prices were expected to vary from house to house according to the size of the roof and its orientation, etc.). We asked each firm about:
Price per property for installation etc. of a grid-connected solar array
Price per property for appropriate battery
Discount per property if the project were for 25 or more households
Health & Safety, including precautions against CV 19
Sub-contracting, e.g. for scaffolding
Contracts, rectifying snags, etc.
The firms sent back much documentation, about the panels they were likely to install, about the inverters (required to convert the DC which the panels generate into usable AC power) and about batteries; also about their working practices, contracts etc.
The working group met by Zoom on 8th July 2020 and we pooled our knowledge and understanding of the bids; agreed to include design of panels in the evaluation (we preferred black); and discussed differences between the firms’ contracts and documentation. We decided to recommend to residents two firms – ASK Renewables and Carbon Legacy. (See at end for contact details.)
3. Open-Air Real Live Socially Distanced Meeting
Both these firms said they were willing to come and talk to residents, and several of the households who were in touch said they would like to meet and discuss the scheme. We fixed Saturday 1st August as a good date; and Joanne was happy for us to have the event on the un-enclosed grass space outside the SSC. We wanted a serious hearing and discussion, and above all a safe one. So we only invited people who’d already been in touch. Just under 30 people came, from 20 households. The weather was kind, we could all hear and be heard (only one noisy aircraft interrupted) and we learned much about both theory and practicalities.
From there on it’s been up to each household to make contact with and deal with one or both of these firms – and if satisfied with what’s been offered enter into a contract with the chosen firm.
4. Covenants with Joseph Rowntree Housing Trust
When we bought our houses we accepted a covenant to get consent from JRHT before installing solar panels on our roofs. They agree in principle. Each household should, before committing themselves to a date for starting work on site, send them details of what’s proposed: number of panels, fixing detail, how they ‘ll be arranged on the roof – a drawing if possible. Both the firms are aware of this and will help supply the details. We need to allow 3 to 4 weeks for the trustees’ consent to be obtained.
5. Other consents
In order to connect the electricity you generate to the grid (so you can sell any surplus) you need consent from the DNO (District Network Operator). This may take time – but the installer will take care of the process. The one for our area is Northern Powergrid – for enquiries ring 0845 070n7172.
6. Update latest
ASK Renewables say that they have contacted the names on the list we sent them. They have done 11 visits and issued quotes on each; 2 have applied to JRHT for consent. They have a further 7 visits planned. Carbon Legacy have 20 people on their list as interested in having a site visit, have visited 9 and booked another 5 for September. Their first 9 quotes are ready to go out.
7. Is it too late to join in?
No! Send your name and address, email and any other contact details to either or both of the recommended firms, and they will make all the necessary arrangements with you. Or give them a call!
Since we put a small item in the most recent LotsOn (late May) we have had 20+ households say they are interested in a group scheme to purchase solar panels, hopefully at a discount. That’s not the end of the story! We hope that many more Derwenthorpe residents will choose to take part – the main benefits being that you catch your own electricity direct from the sun; and by so doing you can help reduce emission of greenhouse gases and therefore our impact on the climate. And we expect that buying in bulk, from a properly accredited installer, will give each of us savings and other benefits as customers.
We approached twelve firms which came up when we followed the link to “Trusted Traders” in this field; plus two which JRHT have worked with on recent solar panel projects locally. The replies vary in level of detail, but there’s plenty of interest in doing the work for us.
We also asked Richard Partington, architect for Derwenthorpe, about any special considerations which might apply here because of our special design features. His reply was very positive:
at projects in Portsmouth and Nottingham they put panels on east- and west-facing roofs, not just south-facing, and “the efficiencies have greatly exceeded expectation”.
if you have a sloping ceiling on the top floor the line of insulation follows the ceiling so make sure any penetrations for cables etc. are minimal and executed neatly.
ask for advice about the best position for the associated kit (inverter, battery, meter, controller etc.) as it makes sense to group these together.
We’ve kept JRHT informed. We have to obtain their consent for solar panels on roofs, and it will be up to each of us to obtain this formally, but they are in favour of this project. We’re hopeful also that they will find space for a compound for the installation firm to use – which should save the firm, and us, time and money.
We have written to five firms with a Request for Information, inviting them to tell us what they can do and asking about:
price per property for panels
ditto for batteries
discounts for larger numbers of houses
health and safety
whether they would they want an on-site compound
contract arrangements with householders.
Other things (apart from cost) for us as residents to think about are:
where in the house to site the associated bits (inverter etc.)
whether you want a battery (to store electricity gained in the day, for use at night) – and if so where (heavy, so best on ground floor)
whether you want to be able to charge a car from solar power, now or in future.
Once we have the firms’ replies we residents will have a discussion about the merits of each, leading to a decision as to which firm to work with. This will probably be a Zoom meeting involving the people who’ve been in touch so far. But we will also be open to comments, expressions of opinion and preferences from people who don’t want to or feel unable to take part in the Zoom thing. If you haven’t already been in touch about solar panels, you’re welcome to do so now (without obligation to commit to having the panels installed): email firstname.lastname@example.org
The next stage after that will be to send round a house-to-house questionnaire, giving a bit of relevant information and asking everyone to say whether they want to be part of the scheme (again without obligation).
Then we’ll go back to the chosen installer and work out arrangements for start on site; how they will deal with each householder; and how they want to organise progress of the work from house to house. Scaffolding will be involved!
Nick Hall, 38 Derwent Mews, YO10 3DN, 16th June 2020
Work in progress last year at one of the houses in Derwenthorpe
Most of us didn’t get a user guide to the home, so some residents have written one. It’s a living document. Please let us know how we can improve it, in the comments below.
For example, did you know your windows have a built in wedge, that you can use to prop them open. Useful, if you need fresh more air while self isolating!
We think we are all really lucky to live in such beautifully designed homes that have many ‘green’ features. Some of those features were new to many of us, so we have put together these simple and non-technical user guides to our homes.
We have based this very general guidance on our experiences and research. While many features of our homes are the same, there are also quite a lot of variations, so you may find differences in your place. However, we hope this guide gives you a good starting point. It is offered to you in the spirit of neighbourliness and community — we obviously can’t accept any liability for actions you take based on these guides!
We welcome further questions and your feedback. Please email email@example.com.