What can you change in a Diagonal Mar tower apartment, and what can't you?
Inside the apartment you can change almost everything: partitions, floors, ceilings, kitchen, bathrooms, lighting and services. Facade, glazing, balcony railings and outdoor units belong to the building, and any change to its outward look goes through the community. The law requires you to notify its representative of the works beforehand.
In Catalonia the rule is article 553-36 of the Catalan Civil Code, not Spain's Horizontal Property Law: it lets you carry out works in your own unit as long as they do not harm the other owners or the community, reduce the building's soundness or accessibility, or alter its configuration or exterior appearance.
Diagonal Mar is not like Barcelona's old quarters. These are modern high-rises by the sea. The structural frame and the walls of lift and service cores are off limits, while internal partitions can usually be moved with a design. The limits here more often come from the tower's uniform look and the complex's own rules than from a protected historic facade.
Ask for three documents before the first meeting with a designer: the community statutes (estatutos), the internal rules (reglamento de régimen interior) and the minutes of the last owners' meeting (acta). Large complexes often have a second tier of governance, an umbrella association with its own rules on exterior appearance and deliveries. You learn that from the property administrator (administrador de fincas), not from the sales brochure.
Can you change the windows in a tower by the sea?
You cannot change the glazing profile or colour without a community decision, because it alters the building's exterior. Replacing the glass inside the existing profile with acoustic or laminated glass is easier, but it is still better to get that approved in writing. If the tower already has a standard design for enclosing balconies, the joinery order is matched to it: profile series, RAL colour, glass type and thickness.
When there is no standard, a request with drawings and samples goes to the owners' meeting. The next meeting can be several months away, so glazing is requested first, before the finishes estimate. Windows and sliding systems are ordered only after written consent: manufacturing usually takes weeks, and redoing an order costs more than the paperwork mistake itself.
If the problem is noise, changing the glass is often a better buy than changing the frame. Asymmetric panes of different thickness and laminate with an acoustic interlayer cut noise better than two identical panes in a new frame. The general approval route for replacing windows in Barcelona is in our article on the permit for changing windows on a facade.
How are materials brought up into a high-rise?
Through the goods lift or the main lift, in a slot booked in advance. Anything that does not fit in the cabin is cut and assembled on site, or hoisted over the balcony by crane if the community allows it. Logistics shapes the budget and the schedule as much as the choice of finishes.
Before ordering, measure the inside of the cabin, the door opening, the cabin ceiling height and the maximum load. Large-format porcelain and quartz slabs of about three metres, door leaves, floor-to-ceiling glass and one-piece kitchen worktops do not fit a normal cabin. Each of these items needs its own decision: a different format, fabrication in parts, or lifting from outside.
Construction waste goes down in bags in the same lift at agreed hours, and a skip on the street needs the city's permit to occupy public space. In practice every extra lift trip means crew hours wasted. A wrong cabin measurement for a slab or a door costs weeks, because stone and glass are made to order.
Which community rules do you have to follow?
Notify the community and the administrator in writing before work starts, keep to the hours and procedure in the statutes, and protect the common areas. The rest depends on the building: some towers ask for a deposit or insurance, others settle for a schedule and a list of workers.
The notice usually states the scope of works, start and finish dates, the contractor and key subcontractors, a civil liability insurance certificate and the contact of the person in charge on site. The lift cabin and the lobby are covered with protective panels, and common areas are cleaned daily. Noisy work (hammer drilling, cutting) happens only in permitted hours: the city's ordinance sets the general hours, and a building may be stricter.
Anything touching common property needs a vote of the owners' meeting rather than a simple letter: facade, risers, ventilation shafts, structure, exterior glazing. The owner is liable for damage to the lift and lobby, since the law requires them to compensate damage caused by their fault or by people they answer for. Ask for the contractor's insurance in advance and check its limit.
What do wind and sea do to noise and windows on a high floor?
On upper floors wind loads on the glazing are higher, seals whistle more often and rain arrives almost horizontally. For windows and sliding doors, looks matter less than the classes for air permeability, water tightness and wind resistance under EN 12207, EN 12208 and EN 12210, plus proper drainage at the threshold.
Before replacing anything, watch how the old windows behave on a windy day and ask the neighbours one floor up. If a closed window is meant to keep noise out, you need controlled ventilation: acoustic vents in the frame or a ventilation unit with heat recovery. Without it, humidity builds up quickly in a closed apartment by the sea.
Climate control is decided together with the glazing. In towers the community often fixes where the outdoor air-conditioning unit goes and rarely permits the facade. The options are a ducted system with the condenser in the assigned area, or a multi-split with a single unit in a technical space. We cover this in more detail in the article on air conditioning without an outdoor unit on the facade.
Which materials stand up to sea air?
Anodised aluminium and aluminium with marine-grade powder coating, A4 stainless steel (AISI 316), porcelain and sealed stone hold up well. The weak points are galvanising without extra protection, cheap hinges and fixings, and MDF board in damp areas.
What suffers most is whatever faces outside: balcony railings, window and door hardware, terrace furniture and the coil of the outdoor unit. Railing fixings go in A4 steel, and where aluminium meets steel an insulating gasket goes between them, otherwise salt brings galvanic corrosion. Timber on a balcony only works with an exterior-grade finish and maintenance every year or two.
Inside the apartment the main enemy is not salt but humidity and condensation. Bathrooms and shower niches get full waterproofing, and wardrobes on outside walls are set off the wall so air can move. We covered materials for a first-line villa separately; in a tower the exposure is lower, but on the balcony and the hardware it is the same.
How do you run a tower renovation if you live outside Spain?
Name one person in charge on site and one language for dealing with the community. Letters to the administrator, the lift booking, passes for workers and the handover of common areas are best delegated to someone who is in the building every day.
BCN YARD runs projects in Russian and Spanish. At the first meeting, confirm who will handle correspondence with the administrator, the lift request and the delivery schedule. One person is responsible for the project. As a price guide: Premium from 1,000 €/m², Luxury from 2,000 €/m² and Signature from 3,000 €/m², excluding VAT; the exact price comes in the estimate after a visit and measurements. VAT on renovating a resale home in our estimates is usually 21%. The 21% applies because in our renovations materials usually exceed 40% of the taxable base; when they do not, renovating a private individual's home is taxed at 10% (Law 37/1992, art. 91). We reply to an enquiry within an hour.
Frequently asked questions
Do I need the community's permission to renovate inside a tower apartment?
For work inside the apartment a vote of the owners' meeting is normally not needed, but the law requires you to notify the community's representative beforehand. A vote is needed if the work touches the facade, glazing, risers, shafts or structure. In practice the administrator asks for a schedule, contractor details and insurance, so send them together in one letter before work begins.
How much does a Signature-level renovation cost in Diagonal Mar?
Our guide for the Signature level is from 3,000 €/m² excluding VAT, with the exact price given in the estimate after a visit and measurements. In a tower logistics adds to it: lift booking, hoisting large pieces, protecting common areas. Glazing and climate control are approved separately, and their cost depends on what the community decides.
Can I put an outdoor air-conditioning unit on a tower balcony?
It depends on the statutes and the community's decision. In many tall buildings the spot for the outdoor unit is fixed in advance, and units on the facade or on balconies visible from outside are not allowed. If there is no space, a ducted system with the condenser in a technical area is considered. Ask the administrator before choosing the equipment, not after buying it.
Who pays if workers damage the lift or the lobby?
The apartment owner answers to the community: the law requires compensation for damage caused by their fault or by people they are responsible for. They then claim against the contractor. So before work starts, ask for the civil liability insurance certificate and photos of the lift and lobby taken together with the administrator.