People replacing windows usually talk to salespeople first. That is normal, but a salesperson earns from the sale. Before you decide, it is worth hearing from someone who does not earn from what you choose. In Portugal there are three services linked to ADENE, the energy agency, that serve this purpose.
This guide says what each one offers, according to its own pages, and what it does not say. We do not recommend or rate them: we point to where they are.
Rede Espaço Energia: citizen support counters
The Rede Espaço Energia page describes it as a network of counters that give information and personal support on saving energy. The footer says ADENE runs it, with funding from the Fundo Ambiental.
According to the page, the counters:
- explain energy bills and consumer rights;
- advise on choosing efficient or renewable equipment and solutions;
- give technical support to find ways to make the home more efficient;
- guide you on incentives and grants, including help with applications.
To book, use the booking page, the email [email protected] or the nearest counter.
What the page does not say: whether the services cost anything. Check when you book. It does not mention energy certificates or windows in particular either.
Portal casA+: home profile and list of professionals
Portal casA+ is developed by ADENE. Registration is free. Once you link the home’s energy certificate, it shows improvement measures with guides and tips. It also has a list of professionals by area and region, in several specialities, among them efficient windows, and lets you request quotes.
What the page does not say:
- how the professionals on the list are checked;
- whether they pay to be listed;
- whether the quotes are binding;
- how the savings statistics it shows are calculated.
Use the list as a source of contacts, not as a guarantee of quality. To check a company, see how to check a company.
SCE technician search
The SCE portal, the Energy Certification System, has a technician search. It lists qualified experts (peritos qualificados) by region, district and municipality, or by name or number, and lets you send a contact request. The page says ADENE does not store the data of that request, which goes to the technicians you pick.
Qualified experts appear under the categories of certification of housing buildings and of commerce and services buildings. The search has another list too, of technicians for technical systems, energy management and inspection.
What the page does not say: what an expert does for you in a window replacement, or what they charge. And it does not list window installers. An expert assesses the home and can tell you in writing how it performs. Whoever fits the windows is someone else.
When an expert helps
A qualified expert does not sell windows, but we do not know what they charge. It may make sense to talk to one when:
- the work is large and you do not know whether it is a «major renovation» (cost above 25% of the building’s value), which changes the rules on ventilation and the solar factor;
- you want to confirm the climate zone of your building. See the page for your town;
- you need to know whether the home already has the minimum air change rate, which the Portaria says to calculate with the SCE Manual method.
Ask the price and what is included before you book.
And JanelaCerta.pt?
JanelaCerta.pt does not sell windows. When you leave your phone number in a request, we pass the request to companies in your area, which send you quotes. We are not independent of whoever receives those requests: that is why we show the sources of the figures and say what we could not confirm. See the methodology.
Sources
- Rede Espaço Energia (ADENE): services of the counters and ways to book. Read in October 2026.
- Portal casA+ (ADENE): free registration, measures, list of professionals, quote requests. Read in October 2026.
- SCE: Technician search: qualified experts and other technicians, search and contact request. Read in October 2026.
What to do next
- See what support exists: window grants.
- Compare quotes: quote comparison.
- Ask the questions for the installer.