Eco renovation

When we first bought the house, we decided we wanted to renovate it in an environmentally responsible way. However, not everything we tried worked out, so this page covers both what did and didn’t work, which will hopefully help other people who are doing something similar. The beginning seems like a good place to start and for each point where we made an environmental intervention we’ve added a label ‘Eco step”.

Starting point

The house is about 100 years old, built from thick stone walls and was 2 storeys, with animals kept downstairs and fodder above. The lower storey is underground on one side and there was also a goat shed attached to the main house.

When we bought the house, the beams weren’t safe to walk on and roof was near collapse. There was no water, electricity or phone connections, although a neighbour generously let us connect electricity for several years until we got our own connection.

Demolition

Before the works could start the old roof and floor beams had to be removed and we did this ourselves to save money. This probably wasn’t the safest thing to do, but we were intoxicated by the Dalmatian air, the beauty of the place and a great wave of optimism that carried us through this and many other trials.

Eco step 1: Re-use of materials

The old roof was tiled with irregularly shaped flat stone which would have been quarried locally and brought to the house, probably by donkey. We decided to remove this carefully and re-use it later in the building process.

Unfortunately, on the first day the builder started he removed it all and dumped it off site. Although I accepted this at the time, in retrospect I think it was probably taken and used on another house because people pay for this kind of material, so in the end it probably was re-used, just not by us.

Main building works

The first phase of the building was completed by local builders including an extra storey, new floor beams, a new roof, new doors/windows and a new extension replacing the old goat house. A friend of ours helped draw up a specification and we had a detailed quotation from one builder, while the other just gave us a single figure. The former got the work because he was more communicative and was also less than half the price.

Crucially, this decision took us down the road with a builder who was strong on concrete and weak on aesthetics, instead of an ‘artisan’ builder who knew how to work with stone in the old way. This would have big implications on the finish of the house.

Eco step 2: Use of local stone

The builder sourced stone from a quarry on the island and despite his preference for finishing the inside of the walls in concrete, we insisted on stone throughout the wall as in the original walls below.

Eco step 3: FSC timber

For the floor and roof beams we sourced FSC certified timber from a sawmill near Zagreb which was delivered to the island and installed by the builder.

Eco step 4: Doors and windows

We found a local artisan in the next village who made wooden doors and windows and he produced and fitted everything we needed for the house.

Floors & stairs

After the builders had finished we had another storey on the house, a watertight shell and floor beams on two levels, plus a terrace above the old goat shed, but no floors, stairs, toilet or kitchen because we had no more money to pay for this.

The next year we had a load of floor boards delivered which we nailed in place one by one with our legs hanging off the edge in mid-air. At night we slept on the bit of the floor we had finished and before long we had clean new floors on two levels with a ladder in between.

Eco step 5: Raised kitchen floor

In conventional construction our ground floor room would be ‘tanked’ as it is half underground. Tanking involves installing a thick plastic sheet to all surfaces of the room to create a water impermeable surface. As a result it has a high energy and environmental footprint and can lead to unforeseen problems such as runoff and damp appearing in other parts of the building.

Instead of this we decided to construct a suspended floor built off masonry blocks and wooden beams, with an additional partition wall constructed away from the underground back wall, allowing a space for ventilation. This provided a route for water runoff and water vapour to escape without damaging the construction materials or finishes.

Eco step 6: Spiral stairs

We built the spiral stairs quite slowly over 2 or 3 years using locally sourced FSC certified timber.

Bathroom & kitchen

We installed these over several years using conventional fittings and appliances

Eco step 7: Pipework

For the whole house we used copper pipe which is more expensive but far better environmentally than plastic as copper is highly recyclable.

Eco step 8: Solar boiler

Although we couldn’t afford solar panels at the time, we bough an electrical boiler with connections to allow future connection to solar panels.

Eco step 9: Kitchen units

The units were built from scratch using FSC certified timber.

Jungle room

The new room under the terrace was constructed from aerated blocks which are typically used for construction in this region. The finish is red block with cement pointing which requires a render and painted covering.

Internally, it was just a bare single room and we decided to convert it into a small double bedroom with en-suite bathroom.

Eco step 10: Lime

Instead of using conventional a cement based render we sourced quicklime from the mainland and slaked it to produce a lime based render which we applied externally to the jungle room and internally within the house. We also produced a limewash which was used to paint the render after it had hardened.

Our experience with lime were quite mixed; the render on the exterior held up fairly well but in those locations were there was more physical wear (e.g. on the terrace walls where people inevitably kicked the walls sometimes) it did not stand up and we had to replace it with a conventional render applied by builders.

Internally, the limewash worked well at first but after a couple of years started to disintegrate and spread a fine white powder around the house which continually had to be cleaned up.

Eco step 11: Insulation

The main house is difficult to insulate, partly because quite a lot of the finish has been completed and this would have to be repeated if insulation was added. We also don’t need heating for most of the year so decided to add a wood burner in the kitchen and insulate the jungle room to provide a warm bedroom for winter use.

We used 50mm of hemp based wall insulation, sourced from a company near Zagreb, installed behind a vapour barrier. The floor and ceiling were also insulated with eco insulation from the same company.

Eco step 12: Wood cladding

The internal finish for the jungle room is FSC or PEFC certified timber.

Eco step X: Rainwater harvesting

Early on we planned to install rainwater collection, storage and re-use via a secondary set of pipework to toilets and the washing machine. We bought and installed a large water tank in the garden but didn’t connect the pipework.

After further research we discovered that the net environmental benefit of rainwater harvesting was negative and so this measure was abandoned.

Given that we had already bought the tank, the additional energy and material use of the pump, gravity tank and secondary pipework probably would not have exceeded the benefits but the complexity of replacing pipework already installed and operating pumps etc. for minimal benefit didn’t encourage us.

Future measures

Most of the future work is in the garden, although we do hope to finish the main house pointing with a local artisan builder who installed our chimney. Further eco-steps should include;

  • FSC Timber fencing
  • Solar thermal panels to heat boiler
  • Solar PV modules to provide electricity
  • Compost bin