I spent a few days building a new roof in South London. We used gabion cages filled with a mixture of large stones and logs to create habitat.
I also used a time lapse camera for the first time to try and capture building the roof. I have divided it into 3 sections, first the set up, including adding some insulation. We used gabion cages from Devoran metals for the edges https://devoran-metals.co.uk/
Edges and protective fleece in place
After this we added a drainage layer of aerated clay pebbles, these also add to the insulation and help to reduce overheating.
Drainage layer is added
I struggled a bit with the speeds and lapse times for the videos but slowly getting better. The next step for the roof was to top up the gabion cages and add the soil, we were using Shire substrates who supply an excellent green roof mix.
Soil goes on
Finally planting and seeding. I worked with Rotherview nurseries to get an excellent selection of plants that are growing well at this time of year, including several sedums, campanula and Armeria. We also added lots of wildflower seeds that will start to show their heads in spring or before.
Planting
Overall, we were pretty pleased with the roof as was the client. Looking forward to seeing it develop over the next few years.
This green roof on an extension in Welwyn Garden City is nearly 10 years old and has been thriving. This was the first green roof I made so I was a little cautious about the loading, the middle are is sedum on a foam drainage mat with very little soil. The edges have more soil and substrate so they are able to support wildflowers, grasses and self seeded local plants. Nowadays I would add a lot more substrate but it is still going strong and the recent rain and sunshine combination has got it growing beautifully.
The sedums are quite persistent and even managed to self seed and create a little patch of growth on the gravel driveway which looks great and offsets the potted plants.
This one was retrofitted which encourages caution, you don’t want the roof to fall down but you can find a combination of plants and sedums that will work on almost any flat or gently sloping roof. Even better if you are building a new extension you can specify the roof to take any depth of soil you want for a really fabulous roof with the plants of your dreams. Drop me a line if you want to know more alex@ecoalex.com
This is one that’s growing right now. I built it with the kids using leftover materials from other jobs and an old pallet to stand in for the roof. The rocks in gabion cages look great and it is super green but lacking in the wildflowers that we seeded it with.
This is a small green roof on a modern house in Sydenham Hill. It uses white painted railway sleepers for a frame to match the fascia boards on the house and I think fits in very well.
This was a green roof on a new extension built from reclaimed bricks. The roof had a slope on it meaning we used a different drainage system that also helped retain the soil in place. It also had a watering system added at the top of the slope for the dryer months.
This was a really cool extension using reclaimed materials in Hackney. The green roof was a bit tricky to photograph but you can see the effect of the plants blowing in the wind above the skylight.
A 2 section green roof installed in Highgate as part of an Eco retrofit being carried out at the property. We incorporated reclaimed york stone paving slabs to create a path which was lined with lemon thyme that should grow over it and release a fragrance when trodden on. Some of the existing planters were retained and we used lots of grasses and some saffron crocuses.
Dry air in the house is a good achievement but I have also been worrying about the pollution levels. Two of the three air intakes are located above the back garden and the front one has some good tree coverage between it and the road but it is still a busy traffic area. This made me look at some alternative ways of cleaning the air, I did some googling and came across the NASA research project on houseplants and their impact on air quality. Now before I go any further I do realise that these were controlled tests and we would also need a very large number of plants to get a big impact but I figure it can’t hurt and what I made looks great.
I have been keen to do something with reclaimed wood and also to add some extra insulation to the flank wall in the kids bedroom so I got a bit carried away here and produced this wall made from old pallets with 50mm of woodfibre insulation behind it. I was a bit nervous about this project as it has a bit more of a design impact than some of the other projects, it’s been in a while now though and I am so pleased with the outcome visually.
Insulating the wall and adding pallets
The first thing we did was tour the streets collecting abandoned pallets. I found that ones that were slightly broken already were better as they are easier to dismantle than really well built ones. The kids really enjoyed the collection process and I also got them to stain some of the planks we extracted to add some variety to the wall.
Next step was to get hold of some wood fibre insulation, not so easy for small quantities but thanks to https://phstore.co.uk/ for arranging it for me, delivery costs almost the same as the insulation in small quantities but cheaper than elsewhere and charming service too. I then fixed some 50mm battens to the wall at 600mm and push fitted the insulation between.
The next bit involved a nail gun so was great fun managed to charm the lady at Travis Perkins into giving me a discount and I was off. I fixed them in an offset pattern and tried to group similar widths of board together so it wasn’t too bumpy.
Then we had to make shelves for the plants to grow on. I used the ‘dice’ from the pallets (technical term for the square bits that go in between the pallets) screwed into the wall to support shelves made from more pallet boards. These dice are pretty tough and tricky to drill through, one of them still has half a drill bit in it where it snapped.
Once it was all up we put in the plants, I used Chinese evergreen, peace lily, some snake plants and a cutting from an old spider plant. I also put in a watering system! Well, I bought some globes that you fill up and they drip out over a couple of weeks, they are a bit inconsistent but a lot cheaper than some automated system. I top them up with waste water from kids water bottles and they are still growing nearly a year later.
The other work I did at this time was in the bathroom, not really energy efficient specifically but we re-used the bath, just changing the handles. The sink was reclaimed from another site and we re-used wood from elsewhere in the house. I also looked at improving the ventilation and added a larger inline fan in a kitchen cupboard. This was set to overrun by 20 minutes and helped reduce humidity in the house, more on that in a bit.
After this point we had a new kitchen and bathroom so the opportunities for add on work were limited. Over the next few years the family got a bit bigger and problems with humidity began to increase in the bedrooms. Then, earlier this year the housing association who own the freehold for the property finally got their act together and decided they would replace the windows. I wanted new wooden ones but the majority won out and we got cheaper plastic ones. They seemed to think this would stop condensation but I realised that this will just condense elsewhere if we don’t remove it. I am also concerned about air quality as we are quite near the centre of town and pollution levels are high. So I did some investigation and formulated a plan to coincide with the window works that would deal with humidity and provide plenty of fresh, clean air in the flat.
I initially looked at mechanical ventilation with heat recovery, these systems are either too big or too noisy to install in a small flat and the filters don’t cover as many pollutants as I would like, a NOx filter is even bigger so even less likely to happen. I was still keen on using a bigger fan to ensure extraction from a central bathroom with a fairly long (3m) duct to the outside. Through some work I am doing with the GLA I came across the Aereco system which has a single fan and then extracts in the bathroom and the kitchen.
Boxed in behind an access panel
This extraction draws air in from the other drier rooms in the flat, I put a small vent in each door to allow the air to come through even when the doors are shut. Each room has a humidity controlled trickle vent on one window, this opens wider as the humidity in the room increases to allow more fresh air in. As there is quite a lot of traffic round us I also chose acoustic trickle vents which are larger. They work well but I probably wouldn’t bother if I did it again, I miss the sirens.
humidity controlled trickle vent
Acoustic trickle vent
So I am drawing in dry air from outside, this might be a bit colder but heating dry air is a lot easier than heating wet air so there shouldn’t be an increase in costs. The fan runs all the time at a low speed so again uses very little energy, probably less than £20 a year. It’s also much quieter than my previous fan, I can’t actually hear it in the kitchen where it is located, the bathroom has a small noise because the intake is so close to the fan but still nothing compared to a normal bathroom fan.
Bathroom extract
Fan in ceiling
Kitchen extract and boxed in fan
So the ventilation has been in for a few months now and it does already feel fresher. The true test will be this winter but towels in the bathroom are drier and the summer heat is a little less stifling with the air flow through the rooms. When we installed we got the following extraction rates for the system. This meant at best we would achieve 14.8 l/s, which is above the minimum rates in Part F, but below what Vince from Aereco thinks the performance of the system should be.
After some investigation we changed the louvred grill on the outside to a better one and there was a massive increase of 12+pa at each extract grille. I’ve shown the rates below at 45pa. You can see that there is a performance increase of 2l/s just by changing the Louvre Grille outside.
Finally Vince provided me with the minimum extract rate for the grille as well. This is where our system can provide energy savings as when there is no moisture detected, it can drop to a very low extract rate, way below minimum regulations – Shown here at 4.8l/s.
So we are now halfway through winter and it is all looking good, no condensation that we have found and the towels in the bathroom are drying overnight. Cooking smells are also gone very quickly from the flat and no new mould is growing on the silicon round the bath. In the summer it was a little bit fresher overnight as well, no maintenance needed except washing the covers for the extract grill. No noticeable difference in our electricity use, when we turned the fridge, router etc off the energy usage was so low our monitor registered at 0p per hour.
The only drawback so far is that the plants are drying out, we never used to have to water the plants in the bathroom and now we have killed one of them and only just rescued the other!
This came about through problems with the old boiler rather than careful planning. Firstly I replaced the thermostat with a Smart controller, this was about 5 years ago and the choice was limited but I got an Owl controller which allowed us to control the heating with a smart phone.
This allowed us to monitor electricity use as well as program the boiler simply online and turn it off for holidays etc. The controller was easy to fit as you replace the existing thermostat and use the same wiring. Once this was done the heating started coming on only when the temperature in the house fell below the required temperature we set. The previous controller turned on the heating when it was programmed to, regardless of the internal temperature and waited for the thermostat to turn it off again. This fine control and ease of use saved us 10% on our gas bills straight away.
The monitor really helped us concentrate on electricity use around the house and focus on reductions, however it also coincided with having kids and being at home a lot more so our usage actually went up for each successive year, as shown below. Now they are a bit bigger we are out more and using the meter to concentrate their minds too and starting to take our usage down again:
The boiler was an old Worcester and only about 64% efficient. A fault developed with it so it started heating up radiators whenever we used the hot water so we decided to get rid of it. I did plenty of research and luckily enough this coincided with Ecobuild so I was able to go round stalls there to look at a good range of boilers and ask silly questions. Efficiency of most boilers is well over 90% so my main concerns were how it would fit in my kitchen and reliability. I eventually settled on an Intergas boiler, not quite so common in the UK but it came with a 10 year guarantee and has very few moving parts and good reliability.
Very pleased with the boiler and five years later there have been no problems. We are warmer, the shower works better and our gas bills went down.
Very pleased with the boiler and five years later there have been no problems. We are warmer, the shower works better and our gas bills went down.
