What is eco building?
Eco building / restoration is generally acknowledged these days as socially responsible and also as a financially sensible thing to do both in terms of reduced running costs and better resale values, and this is why the term “eco” is now vastly overused to sell building related products.
Eco building, at least for me, comprises two key areas as follows:
- Ecological build cost: the fabrication and transportation of building materials entails significant carbon cost and can also put toxic substances into the environment, either as products themselves or as by-products of the manufacturing process.
- Ecological running costs: when (normally significantly later and after more costs than planned!) that happy day arrives when the workers and their angle grinders and cigarettes vacate the site and you can move into your home, normal running costs start.
The biggest running cost by far is usually power for heating and cooling, but power for other uses (lighting, electrical appliances, etc.), water consumption and environmental pollution are also significant ecological costs, and in general these ecological costs correlate closely with financial costs.
So, whether for moral or financial reasons (and it’s normally a mix of the two), most property renovators in Europe want a strong “eco” slant in their renovation. This is fine in theory, but we need only look to almost all European governments to see that when eco starts to trouble the budget the phrases “not practicable” and “not financially viable” are often not far away – short term, eco costs.
Considerations for eco building
If you have the budget and the know-how (and it may also help to speak German) to integrate in your plans, source and include the latest green technology solutions in your restoration, great!
Otherwise, these are the problems you will hit that will put the eek! In your eco when trying to restore a property in Galicia:
- Sourcing and installing: a high percentage of the materials used in a renovation simply aren’t viable to get shipped to Galicia from outside the local area (or at least Spain). Then, even if you can get the materials and items you want to your site, can you find local labour to install them properly?
Builders are generally optimists (except when they’ve already started your build and you are discussing deadlines and costs with them) and will normally shrug off any worries about whether they can understand 79 pages of highly technical instructions in German to get your shiny new eco-system installed and set up. From experience I would say that, high cost low weight electrical things apart, if you can’t get it locally then don’t include it in your plans and also if your builders haven’t installed that system before, don’t let yours be their first time.
- Suitability: some eco systems require certain types of climate to work well. Galicia can be characterised as having a regular mix of sun and heavy rain, generally being damp and humid, and as having temperatures that do not vary hugely with the seasons due to the influence of the Atlantic (this applies less the further inland you go) and also of having less of a variation between summer and winter daylight hours than northern European countries.
More specific issues are that in many rural properties your water supply may well be gravity fed spring water, in which case water consumption is a non-issue from an environmental point of view.
Electricity supplies are often limited to 30 or 40 amps for your whole house, so any high power electrical system may not be suitable.
In Galicia they like to grow eucalyptus (which grow very tall very fast), so even if your south facing aspect has clear sunlight all year now, if you don’t own the land for some distance to the south then it might not in less than 10 years when you are in the shadow of a wall of 30 metre high eucalyptus trees for the 4 months of the year you need the sunlight most. Etcetera.
Basically you have to pick and choose which eco solutions are appropriate for your project both now and in the foreseeable future and include those and only those right from the initial planning stages.
- Bureaucracy and regulations: If you didn’t know it already, once you start trying to do anything in Spain you will soon learn that there is a hideous mass of regulation concerning all manner of things and that the very many august and excellent branches of Spanish and Galician bureaucracy are not there to help you. You would think that eco building would be encouraged, and it is in theory and in certain practical ways (eg. all new builds must have 2 square metres of solar panels linking into their domestic hot water systems), but in other ways regulations can make some things which are eminently good and sensible so burdensome that they simply don’t justify the hassle of trying.
This particularly applies to one key eco area at the moment and that is electricity generation using photovoltaic solar panels which the Spanish government has decided it wants to tax the use of.
I can’t claim to have a clear understanding of the current situation and whether this proposal has actually defeated the challenges to it and become law, but in Spain there is a general fatalism embedded in the population that accepts that the government does what it wants, and there is also often more than a whiff of laws being made at the behest of the vested interests backing whichever political side is currently in office (eg. PP supporting power producers who are no fans of generous feed-in tariffs for small scale electricity producers).
My advice would be that if you have an eco-solution in mind that is subject to specific Spanish government regulation, put it out of your mind and your plans unless you are very, very keen on it.
- Cost vs benefits, longevity, and stage of development: Whether a system is truly fit for purpose and how long an installations service life is is a consideration, as replacing a system invariably costs more in both financial and environmental terms than maintaining an existing system.
Finally, with any proposed system the stage of development of that technology needs to be considered – if it’s a stable and mature technology (evacuated tube collectors, for example) then it’s unlikely to get significantly better or cheaper in the near future, but if it’s a developing technology (photovoltaic solar panels, although less so in the last few years) then you need to weigh up whether it’s economical and also reliable and proven at its current stage and also whether future iterations of it are likely to have backwards compatibility to work with your installation.
Eco solutions suitable for Galicia
Taking all of the above into account, here is a headline summary of the main eco solutions available for providing the heating and domestic hot water that are the major component of a house’s energy needs, and their suitability for Galicia:
- Solar thermal collectors: these are solar panels that heat water for heating and domestic hot water use, and to my mind they are the most effective eco solution for Galician renovations because they are highly (up to 90% for a good quality panel in certain conditions) efficient, can be fitted by Galician plumbers, are readily available in Galicia at reasonable prices and aren’t overly expensive or complicated. To use this solution you need a clear (from shadows) aspect from at least south east to south west from your site.
These can be mounted on a roof, but for maintenance, ease of fitting (and not making mounting holes in your roof that may then cause leaks), and because the optimum elevation angle in Galicia is about 60 degrees, these are better fitted just above ground level if you have a suitable site.
If you use up to (typically) 3m2 of panels then the energy produced is not likely to exceed your domestic hot water usage, but if you have a larger array of panels then you should be able to provide all your domestic hot water needs and also some of your heating needs from your solar panels.
Solar panels can be connected (via a heat exchange tank) to a water radiator system, but their best use for heating is via an underfloor heating system. Therefore if your project requires a concrete ground floor to be laid you should definitely consider incorporating underfloor heating tubing in the slab.
Underfloor heating heats by conduction instead of convection, which is just better in so many ways, but can’t be adjusted rapidly and therefore is best suited to providing background heat with fast top-up potential from a wood burning stove (actually quite eco in many areas of rural Galicia where wood can be sourced with little or no transport cost, and cheaply), pellet burner, electric or gas heater.
- Photovoltaic solar panels: in an ideal world all new roofs and even south facing walls would be made out of photovoltaic tiles and most domestic buildings would be net producers of electricity.
Restoring a property on a budget in Galicia is not, however, this ideal world. Photovoltaics are still not particularly efficient (typically less than 20%) and are also comparatively expensive, although both of these factors are changing for the better all the time.
In addition to this they are best used connected to your electricity supply (and feeding back into the grid), but in Galicia this is subject to new regulation, which will mean, in the Spanish tradition, subject to change, taxation and bureaucracy that outweighs any benefits.
If you do want to use photovoltaics then consider trying to use them in a closed system with something electrical that gets used more when the sun is shining (air conditioner, freezer, irrigation system, etc.) and also bear in mind that voltage converters and batteries to provide continuity don’t come cheap.
- (Air source) heat pumps: Although these consume a fair amount of electricity a good quality one is some 4 times more efficient than running electric radiators. With Galicia’s mild winter temperatures (especially in coastal zones) these are an excellent solution either for heating air within a building or powering a water based radiator or underfloor heating system.
Good, modern air to air pumps may also have dehumidification and heat recovery functions that make them an ideal solution for Galicia.
In colder, inland parts of Galicia it may be worth considering a ground source heat pump, but near the coast the moderating influence of the Atlantic means air source is a much cheaper option because its installation costs are so much lower.
- Pellet and log burning stoves: Pellet stoves provide a good source of heating either for a room or for a whole house heating and domestic hot water supply (with minimal electricity usage). As Galicia has extensive eucalyptus and pine forestation and several companies which manufacture pellets from locally sourced wood, pellet stoves are a cost effective and also eco-friendly heating solution. Likewise, so are wood burning stoves if you can source wood locally and don’t mind the mess.
Eco solutions & construction for health & comfort
Moving on to a general recommendation for a reasonably eco-friendly new build or restoration solution for a Galician house it’s necessary to also consider how to construct for comfort and health (as covered in detail in our constructing for comfort and health section).
The six key areas to consider are:
- Humidity (control of)
- Damp (prevention of)
- Radon (prevention of)
For a new build or a substantial restoration of a property I believe the following set of general guidelines makes the best sense from both an eco and a health and comfort sense:
- Replace or repair the roof ideally using natural ventilation to reduce solar gain and condensation and with the addition of as much insulation as is possible and also a moisture barrier on the internal ceiling to prevent interstitial condensation.
- (If reasonably possible in a restoration) Fit a ground supported concrete floor with a damp proof membrane underneath (can also be done to protect against radon) and at least 5cm of rigid insulation underneath and at the sides. Within this slab cast water based underfloor heating tubing suitable for the house layout, and if possible site this attached to the steel reinforcement for better heat dispersal.
- Repair the walls and consider adding rigid insulation (easy to hide behind panelling or plasterboard) inside and a damp proof membrane going up to 1 metre above the height of any external ground on the other side of the wall. After running dehumidifiers (and ideally at the end of a dry spell in summer) to dry them thoroughly, paint the inside walls with a mould resistant paint.
- Use double glazed windows with infra red reflective coating and doors all of which should not feature thermal bridging wherever possible and should not have gaps and draughts.
- For primary heating energy fit evacuated tube solar panels to heat water. As the ideal installation in Galicia is facing due south and at about 60 degrees from horizontal (use much less than this and there is significant risk of system damage from overheating in the summer) fitting them on a roof usually isn’t ideal.
As well as for this reason, roof mounted solar panels are hard to fit and access, prone to storm damage, and they also involve drilling holes through your roof structure.
If, therefore, you have somewhere on your land to site solar panels at the correct orientation and angle this is easier and usually better.
As a rule of thumb, 2m2 of good quality evacuated tube solar panels will provide the majority of careful domestic hot water usage all year. For heating a house the area needed depends on the size and thermal efficiency of the house, but 10m2 is should provide background heating for a medium sized house.
There are cheaper and more robust versions of these panels that don’t have an evacuated tube, and often these are a sensible alternative.
- To provide night time heating system operation and as a less weather dependent top-up install an air to water heat pump or pellet boiler connected to the same large heat depository (normally a very well insulated 500+ litre, 1000 litre if trying to heat a large house, tank).
- For primary heating system delivery use floor slabs with water based underfloor heating tubing built into the slab. Where this isn’t possible use water based radiators.
Design the heating system to provide extra heat in bathrooms.
- For top up heating use an air to water heat pump, a pellet stove/boiler or a wood burning stove. Where possible, route (steel pipe) chimneys within the house to recover some of the chimney heat.
- As comfort levels are highly dependent on humidity levels, and for health reasons (the control of mould), I believe an active ventilation system is essential in the winter months in Galicia – without one you will simply never get relative humidity levels low enough.
To be energy efficient the type to buy is a whole house one with heat recovery. Even with this sort of system in place using dehumidifiers in areas of the house susceptible to humidity problems during the winter may be advisable.
- Where possible, fit heat recovery systems to your shower/bath and sink drains.
- Finally, it’s obvious, but use LED lightbulbs throughout. As these don’t produce heat they offer more flexibility about how and where you can install lighting.