Green roof on a bike shed

This is a project I completed back in October, secure cycle storage and a green roof. The client wanted secure storage in the front garden without having a big ugly box taking up all the space for planting and we came up with this elegant solution.

Still flowering in March

As the shed is on the way into the house we planted a number of different herbs which can be easily picked when you are on the way home and also release a scent if you brush past. These were combined with some flowering plants (it was October so not much available) and sedums. The whole roof was also sown with wildflower seeds so should be quite productive in the spring. There are saffron crocus bulbs underneath which may start to appear in late summer.

Freshly planted

The bike shed itself has capacity for 2 bikes but there is a larger 4 bike version or these can be put side by side for multiples. To order.

This type of roof can be more easily accessed by the householder so we can try and create a slightly more formal garden than I would on a normal green roof as you can change the plants around and water and feed them if it is necessary.

The green roof itself has a fleece at the bottom then a drainage layer of aerated clay pebbles before the soil, here to about 125mm depth but the sheds are pretty tough so this could be bigger if required. The sleepers look really good but an alternative would be cobbles in gabion cages depending on what would fit with your front garden. Order page.

My Shabbihaus eco retrofit project part 4 living wall insulation

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. 

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.

My Shabbihaus eco retrofit project part 3 ventilation & bathroom

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.

Aereco fan in ceiling
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.

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.

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!

Showing the snake plant that used to take moisture from the air
Air cleaning snake plants

My Shabbihaus eco retrofit project part 2 Boiler replacement

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.

We also got TRVs installed on all the radiators.

My Shabbihaus eco retrofit project – part 1 introduction

Many of you, like me, will have listened watched or read about a wonderful renovation project where the house has become a wonderful palace of efficiency, costs 10p a year to heat and it’s the most comfortable and relaxing place in the world. You gaze on in envy at the ventilation, triple glazed windows and wonderful insulation. Then comes the tipping point, what did it cost for this the interviewer asks? ‘Oh, only £80,000 on top of the cost of the building work’ and at that moment you realise this is never going to happen in your home.

So, what can you do without breaking the bank? I thought I would share some of my experiences of trying to improve my property on a tight budget, with a low income and the property occupied throughout.

Ideally you would start with a whole house plan for your property, this includes an assessment of the general condition of the place and a list of all the efficiency improvements that it is possible to make to the property. You don’t need to carry them all out and certainly not all at once but it gives you a path for the next 10 years or so, you can also tie this in to any other projects you are planning, redecoration, extensions etc. You can see mine here.

Of course I didn’t start with this, I started when the boiler broke but I have got round to it now and I don’t think I got too far off course. The other thing you should probably do is monitor the conditions in the house so you can get a picture of it’s performance and the effect of the changes you make. I have been even worse at this but have some stats on energy use  that the smart meter collected, otherwise it comes down to ‘we felt warmer’ and ‘the mould didn’t reappear on the walls’. Still I am quite happy and it’s slowly getting more comfortable.

So, what did I and what did it cost, here we go in chronological order with the points where it coincided with other works, details to follow over the next couple of weeks

Gabions and cyclamen, a new green roof in Herne Hill

It’s taken a little while to share this new green roof I built in Herne Hill recently.

There were a number of challenges here particularly the height of the roof with no edge protection, we used a harness to install the edges.

The edges were built using gabion cages filled with cobbles. This created a more natural edge and ensured the stones didn’t roll off the edge of the roof and shatter the tiles below, I think they look pretty cool.

I used aerated clay pebbles for the drainage layer again, really like these rather than the plastic sheets and carrying a bag makes you feel really strong as they are so lightweight. We then put in a protective membrane and covered with ultra lightweight green roof substrate from Shire Substrates.

The roof has been seeded with a mixture of wildflowers and grasses with more to be added in the spring. In the meantime I put in some grasses, sedums and also Cyclamen. I wasn’t really sure about the cyclamen but not much else is flowering this time of year a month later and they seem to have settled in well.

I will add further updates in the spring. There are lots of bulbs in there which should appear soon.

Marlow green roof update

Not all my green roofs are in London, you can see one of my early ones in Welwyn Garden City and this magnificent roof on a garage in Spring Gardens in Marlow

Shows edge detail and flowers
Lots of wildflowers growing here

The roof was installed early this year using Shire substrates and materials from Optigreen. I used expanded clay for the drainage layer and large cobbles to create a more natural looking border.

Wildflowers and sedum

The roof had loads of really nice seeds in it and was also planted with some sedums, aliums and stipa grasses and it has really blossomed tremendously.

the long edge of the roof

Green roof in Wood Green

This is one I did last year that has been growing really well. The roof was on a new extension so the clients were able to design in extra big joists so we could support a good depth of soil on the green roof.

They managed to get a 5m extension so we had a good size to work with even with the skylights. It was waterproofed by the contractor ready for installation.

Roof before adding the greenery
Roof cleaned and prepared for installation

The team and myself laid out a protection fleece made from recycled material on the roof, then we added a drainage layer and put a filter fleece on the top to stop roots growing into it. Then we added the substrate, a special mixture of soil, lightweight aggregates, brick chippings etc, this is designed to keep the weight down, drain easily and also stop the plants growing too tall and need maintenance.

The team lay out the substrate

We put a gravel barrier round the edge of the roof and the skylights to assist drainage and add a firebreak. We also put extra gravel under the downpipe from the main roof of the house so the roof can absorb all the water from the roof rather than have it fill up the drains.

Moving materials is always a problem in London and we had to carry all the green roof substrate through the house and up on to the roof. Luckily Ecoalex has some good strong assistants so I didn’t have to do too much lifting. Once we had put out all the green roof substrate at varying depths we were ready to plant.

Planting, workers grass
Roof ready to be planted

For this roof I had a mixture of mature plants and seeds. I included some Stipa tenuissima (the grassy stuff in the foreground) for the first time to see how it would grow and although it browns a bit in the dry periods it seems to be thriving. We also put in a few varieties of sedum to get some ground coverage including house leeks. Other plants included sea burnet and Sempervivum. I picked up all these plants at New Covent Garden Flower market in the morning a great place to pick up plants in London. But these are just to start the roof, the main coverage will develop over the next three years with all the green roof seeds we have planted I used a couple of mixes of native wildflowers including this one from Scotland that has 20 wildflowers and 3 grass species in the mix . Not all these will thrive initially but over time they should each find their own niche on the roof and grow nicely. Gary Grant likes to describe these seed mixes as an orchestra with all the instruments waiting for the conductor to call them in at the appropriate time in the green roof’s own symphony. Below are some pictures of the roof planted and how it has developed this year. More will be added over time.

Low impact green roof in Marlow

Lots of green roofs going in recently and I need to spend more time documenting them. This one in Marlow on a garage was a new design that I am quite pleased with.

I have been working for a while to reduce further the plastics going into a green roof. I used to work with SUDS (Sustainable Urban Drainage Systems) a lot in the past and one thing I always noticed was the number of pipe manufacturers trying to shoehorn more plastic into natural drainage systems. Roofs obviously need to be waterproof so I can’t change that bit and we need something to protect it from sharp objects etc. Then comes the drainage layer which is lots of plastic sheets, this is important to hold a bit of moisture but also to makes sure it drains effectively. So drainage is important for weight but maybe we can make it of something else. For this roof we used aerated clay balls wrapped in a filter sheet that is held in place with some extra large cobbles. So the plastic is at a minimum.

The cobbles add a really nice touch to the edge of the roof and enhance the appearance considerably especially on a roof like this where there is no parapet. The soil is also held in place by the cobbles and I guess some of it may wash between them but not off the edge of the roof.

The roof has been planted with about 15 different plants, some sedum and ornamental, seeded with 30 different wildflowers and also bulbs planted to come up later in the year. I am monitoring progress and plan to pick up some crocus bulbs in autumn to plant.

Finished roof

If you like the look of this, drop me a line or give me a call 020 8133 0190 and I can see what we can do for you.

GLA warmer homes scheme

I am proud to be working with Retrofitworks on the GLA warmer homes scheme. For the past year we have been providing retrofit co-ordinator services to the scheme and provided new energy efficiency measures for over 250 homes throughout London.

As well as providing new boilers we have been improving ventilation, insulating walls and roofs and helping customers improve the windows and doors of their properties. We have even provided a new boiler for a pensioner living in a caravan.

The scheme involves a number of fully trained Retrofit Co-ordinators developing a plan of energy efficiency measures for the project based on a telephone interview and an advanced energy survey from a Domestic Energy Assessor.

The Retrofitworks retrofit co-ordinator team

Once the measures for the property have been agreed with the homeowner installation is carried out by one of the PAS 2030 certified installers and once complete carefully checked by the retrofit co-ordinator.

The scheme is one of the first to offer this independent verification of the work and this is creating better value for the client and the GLA as the co-ordinator is adding in extra measures for the funds available.

Sustainable living for a sustainable planet