Brookside Lodge is designed to be not just a very nice family home, but an eco-friendly dwelling.
These notes explain how it is an eco-friendly dwelling, or is not!
The basic shape is a simple box.
This minimises the surface area, (where heat is lost), for a given volume of space.
(A sphere would be better, but not so easy to live in or construct.)
It is a wooden building built from trees grown in forests managed in a sustainable manner.
Trees lock up carbon dioxide, a green house warming gas,
whilst the manufacture of bricks and cement produce carbon dioxide.
The external logs provide a strong durable weatherproof cladding to the timber frame house inside.
The logs are cut from pine trees grown near the Artic Circle where the growth is so slow
the wood resembles English Oak in durability.
Count the tree rings on the logs, they are two hundred years old.
In-between the logs and the timber frame is a waterproof breathable membrane.
Water vapour and air can pass through but not water.
The insulation within the timber frame must be kept dry. Damp insulation is not insulation.
Within the 150mm thick timber frame, insulation is in every nook and cranny.
If the builders were about to close off access to a space, they filled it with insulation beforehand.
The Finnish builders installed insulation in the roof from the outside before the roof was tiled
because inserting it from the inside they could not fill every gap in the roof.
After the timber frame was constructed it was completely filled with insulation from the inside.
There was not a gap you could put a finger in.
Inside the insulation and timber frame an air-tight layer was made from 4m x 12.5m rolls of plastic.
The plastic was cut to fit, and where it joined other bits of plastic it was overlapped and joined
with doubled sided sticky tape and the free edge fixed with gaffer tape.
Where the plastic came to a door or window it was sealed to the frame.
It is now mandatory to do air-pressure leak testing of new buildings.
We just escaped the requirement to be pressure tested, but built as if we had to be air-pressure tested.
The air-tight layer prevents warm/moist air from within the house leaking into the insulation
where the moisture would condense in the outer cold insulation. Damp insulation conducts heat.
Care was taken during first fix plumbing and electrics not to penetrate the air-tight barrier.
After the first fixes, the inside was lined with plasterboard or timber cladding to cover the air-tight layer.
In order to provide soundproofing, four layers of plasterboard were fixed between bedrooms,
two layers of plasterboard filled with insulation were fixed between living rooms,
and the ground floor ceiling is double plasterboard thickness.
The plasterboard also provides a thermal mass which delays cooling in the winter and heating in the summer.
All the windows are double glazed with low emissivity glass with 20mm gap filled with argon.
It was possible to get triple glazed windows as they have in Finland,
but our climate in England does not justify such expense.
Although the building is air-tight it does need to be ventilated.
Downstairs the windows are fixed, cannot be opened, but every room has a ventilation panel
incorporating a fly screen if ventilation is required.
In addition there are trickle vents above the windows and flue vent in the floor near the wood burning stove.
On top of all that ventilation there is a free flow of air around the flue through the ceilings
to the roof space which is ventilated to the outside.
Everywhere inside though, is delightfully draught free.
The heat for the building comes from a Ground Water Heat Pump and the building is heated by pipes under the floors.
The ground water heat pump collects heat from water under the ground, typically at a temperature of 11°C,
and raises it to 54°C to heat the domestic hot water and the house.
For every 1KW of energy to drive the heat pump you get 4KW out for FREE.
[If you feel the rear of your refrigerator it is warm
because the refrigerator is transferring heat from the food inside into the room.
The ground water heat pump tries to freeze the ground water and transfers the heat to water in the house.
The heat removed from the water in the ground is replenished by the heat from the rain warmed by the sun.
Unlike wind turbines that require wind,
solar panels that require sunshine,
photo voltaic cells that require daylight,
wave power generators that require waves,
ground water heat pumps can get heat at any time day or night, at any season, in any weather.]
The under floor heating provides even heat everywhere, low down where we are,
not hot spots near radiators or up at the ceiling.
In addition, under floor heating only requires water at a temperature of 50°C
whereas radiators need it at 70°C.
So the under floor heating system can be run at a lower temperature where it is more efficient.
What follows is a list of eco-friendly features and practices:
Galvanized steel guttering and down pipes. They can be recycled.
All the surface water from the roof and block paving goes to soak-ways
over the ground water heat pump underground pipe work.
The insulation above the upper story rooms is 250mm thick, a 100mm more than the walls.
There is no tumbler dryer but a ceiling mounted clothes rack in the utility room
where the freezer and ground water heat pump’s waste heat dry the clothes overnight.
There is an eco-friendly dish washer. It uses less water and heat than a person washing the dishes.
There is no undercoat or paint in the house, no petroleum based products.
All the wood inside and outside is treated with vegetable oil/wax base treatment.
You could consume it without ill effect. (I didn’t!)
The only unnatural thing we did use was 45 litres of Brilliant White emulsion
to apply two coats on the new plaster.
We might add some colour after the plaster and wood framed house has settled down.
Low energy bulbs are used everywhere. The lighting is the simplest you can do.
At times too dim. We must get some more reading lamps.
There is a lot of South facing windows that gather solar heat from the winter sun.
It raises the temperature of the living room by 4°C.
We will have to see how to cope with the summer heat!
The inside of the house is really bright.
The large ground floor windows and external glazed doors, internal glazed doors
and Velux windows in the rooms upstairs all make the inside glow with light.
We do not use paper hankies or paper towels.
We have two compost heaps, one current, the other is last year’s.
We have a vegetable garden.
We are not self sufficient but are still, in January, eating last year’s potatoes and beans.
Once we sort out the garden we will be growing much more of what we eat.
We have no letter box opening or flap in a door.
A letter box is fixed to the outside of the house, no draughts from that.
The foundations and footings were not eco-friendly.
But the house has to sit on something solid if it is to last for hundreds of years.
The roof tiles were not eco-friendly, but we did want to be dry with low maintenance roofing.
The remotely controlled motorised entrance gate and garage door are not eco-friendly
but are not really an eco-threat and gives us great pleasure to use.