Renovating a 'torre' in Bonanova and Tres Torres: 1930s-60s houses

What is checked in a 1950s house before renovation?

First the structure, damp and services: the state of walls and floors, foundations and the base, the roof, wiring, pipes and the presence of asbestos. The survey is done before the design, because its results change the estimate and the plan.

The checklist for a house of that era: cracks and settlement; brick walls or a mixed frame; floors on metal or concrete joists, sometimes with timber; damp at the base from groundwater and missing waterproofing; the roof, timber trusses, wood-boring insects; asbestos-cement sheets and pipes; wiring without earthing; galvanised or lead pipes; old heating and boiler.

For large plots geotechnical trial pits are dug, especially if a basement, pool or extension is planned. The survey is done by a structural engineer and a services engineer, and damp is checked with instruments and by opening walls.

The cost of a survey is small next to the renovation, and surprises found during works are expensive. It is the most sensible first step for an owner buying a house to renovate.

Can you add a storey to a house in Tres Torres?

It depends on the planning rules and the specific plot: adding a storey is possible if height and number of floors are allowed and the built coverage is not exceeded, and impossible if the house is protected. There is no universal answer: you need the planning conditions certificate.

In Tres Torres and Bonanova houses stand in gardens, and the plan usually limits coverage and floors to preserve the green character. If the house has unused building volume, it can be used: an extra floor, an extension, an attic. If not, extension is not possible, however much you want it.

Separately, check whether the house is protected: part of the 1930s–60s houses is in the catalogue, and then volume and facade are protected. You find out through an enquiry to the Ajuntament.

Even if an extra floor is allowed, you must check whether the walls and foundations can take it. The structural engineer calculates the reinforcement. It usually costs more than it looks, so we advise comparing it with extending within the existing volume. More on extending a home in our article.

How much of the plot can you build on?

It is set by the coverage and floor-area ratio in the plan: the percentage of the plot occupied and the total area by floors. The figures for your plot come from the Ajuntament's certificate, not from an estate agent or the previous owner.

Parameters you must know: maximum plot coverage, total permitted area by floors, height, number of floors, setbacks from boundaries and street, and the part reserved for garden. To these are added basement rules: whether it counts towards floor area and whether it can be used as living space or only as garage and plant rooms.

Many 1930s–60s houses are built at the limit or already exceed current rules: then they cannot be extended and the renovation stays within the existing volume. If the house has unlawful additions, they can be a problem at sale or for a licence.

Check the cadastre and the actual area too. It is better to discover a mismatch between document and reality before purchase, not after. The procedure is in our article on checking planning conditions.

Can you build a basement garage and a pool?

Usually yes, if the plan allows a basement and there are no obstacles from ground, water table or neighbouring buildings. A basement garage needs excavation, retaining walls, waterproofing, a ramp and ventilation. It is more complex than it looks on the drawing.

Checks: geology and water table, effect on neighbours' foundations, ramp width and gradient, turning radius, headroom, and the basement use permitted by the plan. A geotechnical report and a design for supporting the excavation are needed. Costs rise sharply on plots with a high water table and on slopes, as happens above Bonanova.

Basement waterproofing and drainage must work for decades: mistakes here cannot be fixed cheaply. For garage ventilation, air changes and carbon monoxide sensors are provided as the rules require.

The pool may sit above the basement or beside it. If it is indoor, dehumidification and ventilation are added. More in our articles on pool permits and on the stages of building a pool.

How do you deal with damp at the base and old services?

Damp at the base is treated by diagnosing the source and fitting a system: perimeter drainage, wall waterproofing, rising damp treated by injection or capillary solutions, and breathable finishes. Painting the wall is useless while the water keeps coming.

In 1930s–60s houses damp comes from the ground through foundations and walls, and also from broken pipes and leaking roofs. So first the moisture is measured and the cause established. Then come drainage around the house, waterproofing, a ventilated lining on the lower walls and breathable lime-based plasters. More on capillary damp in our article on old walls.

Services are replaced entirely: electrics with earthing and a new board, pipework in current materials, heating and boiler, ventilation. In a house with a garden irrigation, garden lighting and outdoor sockets are also provided.

In a full renovation the house is opened down to the structure and rebuilt. It costs more than a cosmetic job but gives dry walls and decades of life.

How BCN YARD works with 'torre' houses

We start with a visit and measurements, arrange a survey of structure and services and only then calculate a staged estimate. Our own crew, trusted subcontractors and one person responsible for the site, in Russian and Spanish. For private houses we have full-cycle experience, including a pool and solar panels.

Payment by contract and in stages. A guide for a high-end renovation: Luxury from 3,000 €/m² before VAT, with the exact price in the estimate. We usually answer an enquiry within an hour.