Renting a flat room by room can lift gross income well above a whole-home lease, but only where purchase prices stay low. In our model, a 3-bedroom flat (T3) in Coimbra let to three students returns about 8.6% cash-on-cash with 80% financing. The same strategy in Braga returns 2.4%, and in Porto and Lisbon it loses money at current mortgage rates.

This guide compares Coimbra, Braga, Porto and Lisbon using sourced asking prices and room rents, shows every step of the calculation, and then stress-tests the result. The aim is to show where your equity works hardest, and how quickly the return disappears when an assumption slips.

Key takeaways: (1) District-average asking prices are about 70% lower in Coimbra than in Lisbon, but room rents are only 11% lower. (2) That spread, not student demand alone, drives the result. (3) A 15% drop in room rent cuts Coimbra from 8.6% to 5.3%. (4) Treat asking rents as a ceiling, not a forecast. To see how we measure the return, read our guide to cash-on-cash return.

What changed in this update?

An earlier version of this guide, published on 11 July 2026, headlined a 12% cash-on-cash return. We rebuilt it on 4 October 2026 because the headline was not supported: the worked example inside the article itself produced 4.4% to 7.1%, and several sources it cited could no longer be found. The numbers below use only sources we retrieved and read, and the model is fully shown. We also dropped Aveiro because we could not verify a current room-rent series for it.

Why is student housing demand structural?

Portugal has long had fewer subsidised student beds than students. In September 2022 the Prime Minister announced a target of 26,000 beds by the end of 2026, up from 15,000, backed by Recovery and Resilience Plan funding of €375 million plus an extra €72 million (Notícias ao Minuto / DNoticias, 15 September 2022). Savills counts roughly 26,000 student beds today, about half in public halls of residence and half in private purpose-built schemes, which is a national coverage rate of 5.8% for a cohort of 456,032 higher-education students in 2024/25, of whom 80,065 are international (Iberian Property, 7 May 2026, citing Savills).

The practical result is that many students rent privately. That demand is real, but it is not unlimited, and the next section shows that supply is catching up in some cities.

What do prices and room rents look like in 2026?

Imovirtual data for July 2025 shows asking room rents of €400 in Coimbra (up 25% from €320 a year earlier), €355 in Braga (down 3%), €450 in Porto (down 8%) and €450 in Lisbon (flat). Nationally, the average asking room fell 10% to €450 while the number of listings rose 88%. Coimbra listings jumped from 89 to 430 (Forbes Portugal, 22 August 2025, Imovirtual data).

For purchase prices we use the Doutor Finanças August 2026 observatory, which averages online asking prices per district on 1 August 2026: Lisbon €5,683/m², Porto €3,749/m², Braga €2,073/m² and Coimbra €1,679/m². Its whole-home rent averages are €19.66/m² in Lisbon, €13.32 in Porto, €9.56 in Braga and €8.67 in Coimbra (Doutor Finanças, Observatório Imobiliário, August 2026).

One useful cross-check: whole-home renting in Coimbra yields about 6.2% gross on those district averages (€8.67 × 12 ÷ €1,679). Per-room letting lifts that to 8.7% in our model, before the extra management cost. That uplift is the real prize of the strategy.

Caveat: these are district-wide asking prices, not transaction prices and not near-campus prices. Lisbon and Porto districts include outlying municipalities, and a flat close to a faculty will usually cost more. Use the figures to screen cities, then replace them with real listings before you bid.

How do the four cities compare?

We model a 90 m² T3 let as three rooms for 11 months a year. The price is the district average per m² times 90 m². Room rents are the July 2025 asking averages above.

City T3 price (90 m²) Rent/room Monthly rent (3 rooms) Gross yield Cash-on-cash (80% at 3.99%)
Coimbra€151,110€400€1,2008.7%8.6%
Braga€186,570€355€1,0656.3%2.4%
Porto€337,410€450€1,3504.4%-2.8%
Lisbon€511,470€450€1,3502.9%-7.3%

Method: gross yield = annual rent (11 months) ÷ purchase price. Equity = 20% down payment + 7% closing costs (IMT and stamp duty, a deliberately conservative blended figure) + €9,000 furnishing. Loan = 80% at 3.99% over 30 years. Operating costs = 15% of rent (condominium, IMI, maintenance). Figures are before income tax. Our other 2026 guides use the same 3.99% cost of debt.

The ranking is clear. Coimbra works because the debt is cheap relative to the rent it supports: an 8.7% gross yield against a 3.99% mortgage. In Lisbon the 2.9% gross yield cannot cover the debt, so leverage destroys value instead of adding it. For the wider picture, see our rental yield guide and the buy-to-let guide.

How do we reach 8.6% in Coimbra?

ComponentValue
Purchase price (90 m² × €1,679)€151,110
Down payment (20%)€30,222
Closing costs (7%)€10,578
Furnishing€9,000
Total equity deployed€49,800
Monthly rent (3 × €400)€1,200
Annual rent (11 months)€13,200
NOI (after 15% operating costs)€11,220
Annual mortgage payment (€120,888 at 3.99%, 30 years)€6,917
Annual cash flow before tax€4,303
Cash-on-cash = 4,303 / 49,800 × 100 = 8.6%
Base case: asking room rent of €400, 11 months occupied, 3.99% mortgage.

You can rerun this with your own prices in our student rental calculator.

What breaks the return?

A single input moving is enough to change the verdict. Here is the Coimbra case with one assumption changed at a time:

Scenario (Coimbra T3)Cash-on-cash
Base case8.6%
Purchase price 10% lower10.9%
Mortgage at 3.5%9.4%
Mortgage at 4.5%7.8%
Operating costs at 20% of rent7.3%
Only 10 months occupied6.6%
Room rent €340 (15% lower)5.3%
Room rent €320 (the July 2024 level)4.1%

Rent is the fragile input. Coimbra's asking rent rose 25% in a year while listings quadrupled, which is exactly the pattern in which rents tend to give back gains. If you underwrite at the 2024 level of €320, the return falls to 4.1%, no better than many whole-home rentals. Underwrite at a rent you could still achieve in a softer market, not at today's asking average.

What are the risks of renting per room?

  • Supply catching up: new listings and new beds push rents down, as the Porto and national figures already show.
  • Seasonality: contracts follow the academic year, so assume empty months. The 10-month scenario above costs two percentage points.
  • Wear and management: three tenants use furniture and finishes harder than one family, and you manage three contracts and three sets of guarantees.
  • Rules and tax: condominium rules and the property's permitted use can restrict room-by-room letting, and rental income is taxable, which this pre-tax model ignores. Our guide to rental income tax (Category F vs B) covers the tax side.

What is a sensible execution strategy?

  1. Pick the city by price-to-rent ratio. On this data, Coimbra passes the test and Braga is marginal. Porto and Lisbon do not clear it with 80% leverage.
  2. Replace district averages with real listings. Price the specific flat, its walking distance to the faculty and its condition.
  3. Underwrite conservatively. Use a room rent about 15% below the asking average and at least one empty month.
  4. Check the legal basics before you buy. Read the condominium rules and confirm the permitted use with a lawyer.
  5. Keep the financing spread wide. Return compresses as the mortgage rate rises, so test your rate at 4.5%.

For other ways to compare strategies, see the cash-on-cash return guide. This article is for information only and is not financial, legal or tax advice.

Frequently asked questions

How much does a 3-bed flat let per room make in Coimbra?

In our model, about 8.6% cash-on-cash: a €151,110 flat, three rooms at €400 for 11 months, 80% financing at 3.99% and €49,800 of equity. At a room rent of €320 the return falls to 4.1%.

Is student rental more profitable than renting the whole home?

In Coimbra, yes on the numbers: about 8.7% gross per room versus roughly 6.2% for a whole-home lease on district averages. The gap shrinks after higher management cost, wear and empty months, and it disappears in Porto and Lisbon where purchase prices are high.

What are the biggest risks of renting per room?

Falling room rents as supply grows, seasonal vacancy, higher wear and managing several contracts. Rent is the most sensitive input: a 15% fall cuts the Coimbra return from 8.6% to 5.3%.

Is it legal to rent a flat room by room in Portugal?

Letting individual rooms is common, but the rules depend on the contract type, the property's permitted use and the condominium regulations. We did not verify a single room-tenancy regime for this guide, so check the condominium rules and take legal advice before you buy.

Sources