Lately I have come across quite a few articles online full of tips for saving money when you build your house. So I thought I would write a post the other way round, setting out the things that, in our view, you should NOT save on when building your home — or, put another way, the upfront costs that lead to long-term savings.
I am too poor to buy cheap is a German saying that makes a great deal of sense. The Germans take the view that the things that matter, such as your shoes or a jacket, have to be good, so that they do their job and last a long time. Let’s apply that idea to a house:
Spend on a good design
You might think I am just looking after my own interests here, but it is one of the things I am most certain about. A good design anticipates things such as future extensions. It sets out the structural grid so that every window and external door can be a standard size rather than made to measure (and so saves you money). It separates day zones from night zones — or even a guest wing — so that the services can later be split into independent circuits. It gets the geometry right and the orientations right, and uses passive climate control solutions. And it does not contain errors that later turn into serious cost overruns during the build. Get all of that right and you will save a great deal of money. An architectural design normally costs less than 5% of what the building work costs, yet compared with a cheap design that is unoptimised or full of errors, it can save you far more than its own fee.
Spend on energy efficiency
On the services side, good solar thermal panels for hot water recover the investment through lower electricity bills in under five years, and from then on you are simply spending less. Services split into proper zones let you shut down the parts of the house you are not using: if you have a guest wing, it should sit on its own circuit that you can close off. It costs a little more at the start and then saves for the life of the house. The same goes for heating and cooling — zoning it by use and by orientation is fundamental. You can use a system such as Airzone, but above all the key is a good services design. There are houses where, at certain times of day, some areas are hot because they get the sun while others are cold at the very same moment. The installation has to have anticipated that, so you can do what each space needs (cooling one while heating another) and avoid running the spaces you do not need when you do not need them. Photovoltaic panels also pay for themselves over time. As things stand, you have to feed what you generate into the grid and sell it to the supply company. If households are one day allowed to store that energy and use what they generate at home, that will be a genuine revolution.
On the construction side, use systems with good insulation that eliminate thermal bridges, and then audit what has actually been built with a thermographic camera or a Passivhaus-style pressure test. Good external thermal insulation (SATE) together with good windows (thermal break, sealed cavity, low-emissivity outer pane) costs more at the start, but it pays for itself over time, and after payback it is all saving. Do make sure the low-e pane has not gone in the wrong way round: you see all sorts on a building site.
There are also systems that do not merely keep heat and cold out, but let outside energy in when it suits you, or even provide cooling. A Trombe wall is one example. A greenhouse effect on the outer face heats a thick ceramic or stone wall of low transmittance. The energy is gathered during the day and reaches the house at night, because it takes a full day to travel from one face of the wall to the other. For the opposite case — cooling rather than heating — there are blue roofs, which insulate and also let you circulate air moved by solar chimneys. A solar chimney has metal elements on the outside that heat up and warm the air inside it; warm air rises, that movement pulls the rest of the air up the chimney, and you have ventilation. Run that air over water at a lower temperature and it cools; bring it out inside the house and you are cooling the interior.
Fit systems that use little water and reuse what they can
Another significant saving in the house comes from fittings that keep water use down, that reuse greywater, and that even collect and reuse rainwater. In the long run, they pay for themselves.
Plant deciduous species
Designs that use deciduous planting to shade sun-facing walls in summer, shielding us from massive solar gain, and then let that energy through in winter once the leaves have fallen, are an excellent solution — and not too expensive.
Ventilate
It sounds like advice from your grandmother. It is not. Make sure the design provides for cross ventilation, and that you can shut it down in winter so you are not throwing energy away, then open it up in summer to ventilate and take the edge off the temperature at no energy cost at all. That is a serious source of saving.
Go carefully with termoarcilla
Termoarcilla (a large-format lightweight clay block) is an excellent construction system with real virtues. The units are big, so the walls go up faster, and it has very good thermal and acoustic insulation. My only warning is this: if you go for it, have it laid by people who are used to laying it, and make sure the purpose-made units are used for the finishing details. It is very common to see bricklayers misuse termoarcilla simply because they do not know it. They finish corners, lintels and jambs with ordinary brick, or with broken pieces of block instead of the purpose-made units designed for the job. That builds thermal and acoustic bridges straight into the wall.
Plan the build properly, and pay someone good to supervise the contractor and the trades
A building site is a lot of separate work streams running over one another. Some things have to happen before others — services before plastering — and some are a bottleneck for everything else: once you have poured concrete you have to wait before you can work on the storey above. A well-designed programme optimises all of that and can save you a lot of money. If you are self-building, do not save on designing that process; hire a good project manager to do it. If you hand the construction to a building contractor, the programme is not your responsibility, but you do need a technical professional of your own (in Spain, the architect or aparejador of the dirección facultativa) checking the quality, checking the deadlines, and checking that what is going up is what was designed. This is another cost that is not worth saving on, because good supervision can save you more money than it costs.
Conclusion
There is a great deal more one could say, but I will stop at those examples and one general idea. When you think about the whole service life of the house — not just the initial investment, but the monthly bill, the annual and multi-year maintenance, the durability — the perspective changes.
Some things are not an expense but an investment. Those are the ones worth spending on.
