GarageInvestor
Methodology

How we estimate yields

The numbers behind the numbers. What goes into every yield estimate on a Garage Investor listing, what we suppress, and where the data comes from.

The short version

On every auction-tagged listing we publish an estimated clearance range and an estimated gross yield range based on it. For non-auction listings (agent and off-market), the asking price is already the price you'd pay, so we show the headline yield with no estimation.

For auction listings we look for at least three comparable sold-price records in the same postcode prefix and unit-count band. If we find them, we publish a range. If we can't, we show nothing. We'd rather say “not enough data” than give you a guess.

What goes into the estimate

1. Comparable sold prices

Our sold-price database tracks every garage lot we've previously listed that has gone to closing, plus a growing library of UK auction-house results. The key fields per record: postcode, region, tenure, unit count, sold price, and sold date.

2. Unit-count band

We group lots into three bands: single (1-2 garages), small block (3-6 garages), and large block (7+ garages). A two-garage comp tells you very little about a twelve-garage block, so we only use comps inside the same band as the listing.

3. Postcode-prefix matching

First pass: we look for comps in the same three-character postcode prefix as the listing (e.g. M21, BS5). This catches sales on the same estate, the same street, or near-identical access. If we find three or more, we use those.

Second pass: if local comps are thin, we widen to the full region (e.g. North West, Yorkshire and Humber). Still requiring three or more matching unit-band/tenure comps.

If neither pass finds three comps, we publish no estimate. See When we suppress.

4. The clearance range

From the comp pool we compute the median sold price per garage unit. We multiply that by the listing's unit count to get a median expected clearance, then publish a range of ±10% around that median. So if the median per-unit clearance from comps is £6,500 and the listing has 8 units, the median expected clearance is £52,000 and we'd show a range of approximately £47k-£57k.

5. The yield range

We divide the annual rent stated on the listing by each end of the clearance range to produce a corresponding yield range. The lower clearance gives the higher yield and vice versa. For the net yield range, we subtract estimated annual costs and add SDLT into the clearance before dividing.

When we suppress an estimate entirely

We hide the yield (showing “—” instead of a number) in four cases:

  1. Guide under £5,000. Peppercorn guides can clear at 3-5× the guide. Any percentage we'd publish would be wildly misleading.
  2. Computed yield above 25%. For non-auction listings, a yield over 25% almost always indicates a data-entry error or a peppercorn legacy rent. We flag it rather than display it.
  3. Estimated yield range tops 25% at the optimistic clearance. Same logic for auction listings — if the high end of the range exceeds 25%, the rent figure is likely anomalous.
  4. Insufficient comp data. Fewer than three matching sold-price records at both the postcode-prefix and regional level. We'd rather say nothing than guess.

In any suppressed case we still show the guide price and rent prominently, so you can do your own underwriting. The Maximum Bid Calculator lets you plug in your own clearance assumption and see the resulting numbers.

What this estimate is NOT

Not a price prediction. Auction clearance is driven by who turns up on the day, what condition the lot is in, and the local market mood. The range we publish is what comparable lots have actually achieved; it's not a forecast for this specific lot.

Not a recommendation to bid. Even when our numbers look attractive, the legal pack, access, condition, tenancies and lease terms can all destroy the deal. The estimate is one input among many.

Not a substitute for inspection. Every experienced garage investor we've spoken to inspects in person before bidding. So should you.

Where the data comes from

Sold-price records are sourced from: completed deals previously listed on garageinvestor.co.uk, public auction-house results pages, and direct submissions from member investors who've closed transactions. We don't use Land Registry data directly because garage sales are often missing from it or filed as part of larger residential sales.

The full track record of how our published estimates compare to actual sold prices is on the track-record page. We update it monthly. If you spot a discrepancy or have a sold-price record to contribute, reply to the Tuesday Brief and it'll land in our inbox.

Rental rates: where the rent data comes from

The rental-rates database tracks what UK garages rent for, by postcode district and region. It draws on the following sources, refreshed monthly:

  1. Achieved rents from a managed portfolio. Rents actually being paid across several hundred garages under professional UK management. These are real, collected rents — not advertised hopes. To protect the commercial position of the landlords involved, achieved rents are published only as aggregates (median and range) and only where a district or region has at least three records. Individual lets are never shown.
  2. Asking rents from national lettings agents. Live public listings from major UK garage lettings operations, covering hundreds of sites nationwide. Asking rents typically sit above achieved rents — a listing sitting empty at £30/week tells you what the market rejected, not what it pays — so achieved rents carry more weight in our confidence ratings, and the per-deal rent benchmarks use achieved records first.
  3. Passing rents from tenanted sale listings. When a garage investment is sold with tenants in place and the listing states the rent actually being collected, we record it as an achieved rent (averaged per unit for blocks). These are vendor-stated figures, so they carry a note to that effect.
  4. Member and manual reports. Rents contributed by member investors and verified entries we add ourselves.
  5. P2P storage marketplace listings. Publicly advertised garage listings from a peer-to-peer storage marketplace (asking rents). Their typical single-garage price tracks the wider market, so they are included — but capped: listings above £250/month are treated as premium marketplace outliers and left out of the medians. Subsidised local-authority (council) rents are tracked separately and kept out of the published figures entirely, as they run around half the open-market rate.

Rents quoted weekly at source are converted to calendar-monthly (×52 ÷ 12). Listings that stop appearing drop out of the statistics after six months. The same suppression rule as our yield estimates applies: fewer than three records at both the district and regional level means we publish nothing rather than guess.

The published figure is the median across all records in the area — achieved and asking together. Rather than pretend a single number carries equal weight everywhere, each figure gets a confidence rating computed from three things: how many records sit behind it, how much of the data is real achieved rent rather than advertising, and how fresh it is. High means 30+ records with at least 15% achieved rents and a median data age under ~2.5 months. Medium means 8+ fresh records. Low is everything else that clears the three-record floor. If our monthly refresh ever breaks, the ratings degrade on their own — stale data can't masquerade as fresh.

Where a deal listing shows a “typical rent nearby” figure, it is the median achieved rent for the listing's postcode district from this database (falling back to asking rents, then to the region, under the same three-record rule).

Methodology changes

July 2026. Launched the rental-rates database — garage rents by postcode district and region from managed-portfolio achieved rents plus national agent asking rents, refreshed monthly. Later the same month we replaced the separate achieved/asking columns with a single typical-rent figure plus a transparent confidence rating (sample size, achieved-rent share, data freshness), broadened coverage with national private-landlord listings, and began including peer-to-peer marketplace listings up to a £250/month cap (premium outliers above it are excluded).

June 2026. Removed the 1.3-1.8× heuristic fallback. Previously, when we had no comp data we'd publish a range computed from a generic auction guide-to-clearance multiplier. Following feedback from experienced investors that this undermined trust in the rest of the data, we now suppress the estimate entirely when comps are thin.

March 2026. Introduced unit-count band matching. Previously a single-garage sale could influence the estimate for a twelve-unit block. The bands now mean fundamentally different lot types don't cross-contaminate.

Questions?

Reply to any email from us, or use the hello@garageinvestor.co.uk address. We read everything.

See how our published estimates have played out

Every estimate we publish gets compared to the actual sold price once the lot closes. The track record page shows the average sold-vs-guide multiple, achieved yields by quarter, and recent sample deals.

View the track record →
How we estimate yields | GarageInvestor