on Google
A property investment in Lisbon can pay off well, but the return depends on more than the purchase price. Tenants compare homes on comfort, running costs and condition, and many Lisbon buildings are old, with poor insulation and outdated kitchens and bathrooms. Well-chosen renovations raise the rent a property can command and reduce the time it stands empty. In this guide we bring together four renovation tips for 2026 and the condominium and municipal rules you need to check before starting any works.
In short
- Energy efficiency: windows, insulation and efficient equipment lower bills and improve the energy certificate, which is mandatory for selling and renting.
- Kitchens and bathrooms: these are the rooms tenants look at first; durable, easy-to-clean materials pay off.
- Smart technology: thermostats, smart locks and leak sensors help with management from a distance.
- Rules: works that change the facade or common parts need the general meeting’s approval, and some works need a licence or prior notice to the City Council.
Before renovating: do the maths
Every renovation should be judged by what it adds to the net return, not by how it looks in photographs. Before spending, estimate:
- the rent the property can command before and after the works;
- the months without a tenant while the works are under way;
- the extra contributions already approved by the condominium, if any;
- the taxes on rental income and the costs you can deduct.
Maintenance works on a rented property are, as a rule, the landlord’s responsibility, whether ordinary or extraordinary, unless otherwise agreed (art. 1074 of the Civil Code). It therefore makes sense to carry them out before a new tenant moves in. The cheapest renovation is the one you only have to do once.
1. Focus on energy efficiency
Many buildings in Lisbon’s older neighbourhoods were built long before current thermal requirements. Draughty windows, single glazing and uninsulated walls mean cold, damp homes in winter and hot homes in summer. These are the most common complaints from tenants and one of the main causes of mould.
The measures with the greatest impact are usually:
- replacing windows with double glazing and thermal-break frames;
- insulating roofs and walls where the building allows it;
- installing efficient heating and hot water equipment, such as heat pumps;
- LED lighting and appliances with a good energy rating.
The energy certificate is mandatory for selling or renting a property, and a better rating makes the advert more attractive. Before replacing windows, check with the condominium: the frames are part of the facade’s appearance and changes may need approval (see section 4).
Solar panels are an option in houses or on roofs that the condominium allows to be used, but the roof is, as a rule, a common part of the building, so installing them requires the general meeting’s agreement.
2. Upgrade kitchens and bathrooms
Kitchens and bathrooms weigh heavily on a tenant’s decision and on the condition of the property at the end of a lease. In older flats, the priority is often hidden: old pipes, worn-out electrical installations and poor ventilation. Fix these first, then the finishes.
| Upgrade | Why it pays off | Watch out for |
|---|---|---|
| New plumbing | Prevents leaks into the flat below | Shared pipes are common parts; involve the management |
| Updated electrics | Safety and capacity for modern appliances | Use a certified electrician |
| Durable worktops and tiles | Less wear between tenants | Choose easy-to-clean materials |
| Extractor fans and ventilation | Reduces damp and mould | Do not open new ducts in the facade without approval |
| Efficient appliances | Lower bills for the tenant | Include them in the inventory of the lease |
Leaks are one of the most frequent sources of conflict between neighbours. A bathroom renovation is the right moment to check shut-off valves and waterproofing. See also the innovation works that add value to the building.
3. Consider smart home technology
Lisbon attracts many international professionals who value convenience and security. Some simple devices improve the tenant’s experience and make management easier for an owner who does not live nearby:
- smart thermostats and timers to control heating;
- smart locks or key boxes, useful for handovers between tenants;
- leak and smoke sensors that send alerts to the phone;
- good internet coverage, which many tenants consider essential.
Devices installed in the flat are the owner’s decision. Anything that affects common parts, such as cameras in the entrance or changes to the intercom, must go to the general meeting, and video surveillance has to comply with data protection rules.
4. Know the regulations and condominium rules
In a building under horizontal property, your flat is yours, but the facade, roof, structure and shared pipes are common parts. The law prohibits owners from carrying out works that harm the safety, architectural line or appearance of the building, and works that change the architectural line or appearance need prior authorisation from the general meeting by a majority representing two-thirds of the building’s total value (art. 1422 of the Civil Code). This includes air-conditioning units on the facade, closing balconies or replacing windows with a different model.
Innovations in the common parts also need a two-thirds majority (art. 1425). Learn more about majorities at condominium meetings.
As for the City Council, some works are exempt from control, while others require prior notice or a licence, particularly in protected areas. Check with the Lisbon City Council before starting and read our guide to building works that require authorisation from the City Council.
Long-term or short-term rental?
The type of rental changes the renovation. A long-term lease calls for durable finishes and good insulation; short-term rentals call for furniture, equipment and a registration that depends on the municipal rules in force in Lisbon. Compare both options in short-term or long-term rentals in Lisbon and see the rules for local accommodation.
Checklist before the works
- Ask the condominium for the latest minutes, the budget and any approved works.
- Check whether the works affect the facade or common parts.
- Confirm with the City Council whether a licence or prior notice is needed.
- Get quotes from at least three suppliers.
- Plan the works for the period between tenants.
- Update the energy certificate when the works improve the rating.
How Condoroo helps
Condoroo manages more than 600 condominiums and also provides rental management, with a team of more than 20 professionals. When you need the general meeting’s approval for works, we prepare the notice and the minutes; with more than 35 inspections a day, we follow up problems in the common parts. Find out more about rental management.
Property investment in Lisbon: frequently asked questions
Which renovations add most value to a rental property in Lisbon?
As a rule, energy efficiency (windows and insulation) and the kitchen and bathroom. They lower running costs, reduce damp and are what tenants notice first.
Do I need the condominium's permission to replace my windows?
If the new windows change the appearance of the facade, yes: the works need prior approval by a majority representing two-thirds of the building’s total value (art. 1422 of the Civil Code).
Can I install an air-conditioning unit on the facade?
Only with the general meeting’s authorisation if it changes the architectural line or appearance of the building. Check the regulations too.
Is the energy certificate mandatory for renting?
Yes. The energy certificate is mandatory for selling and renting a property.
Who pays for maintenance works in a rented flat?
The landlord, whether ordinary or extraordinary works, unless otherwise agreed (art. 1074 of the Civil Code).
Do renovations in Lisbon need a council licence?
It depends on the works. Some are exempt, others require prior notice or a licence, especially in protected areas. Check with Lisbon City Council before starting.
This article is for information only and does not replace personalised legal or technical advice. Legislation checked on 26 October 2026.
