Void Periods: The Metric Most Landlords Never Measure
Gross yield is calculated from annual rent divided by purchase price, and it assumes the property is occupied for all 52 weeks. Void periods are the weeks when no rent is received, and they are rarely measured. A two-week void on a property let at £950 per calendar month costs roughly £438 in lost rent for that year, before any re-letting costs are added.
Why voids differ by area and stock quality
Void periods are not evenly distributed. They cluster where supply of similar stock is high, where tenant turnover is fast, and where the property itself competes poorly against what else is available at the same rent.
Areas with a large private rented sector and a transient population tend to see shorter tenancies and more frequent changeovers. Areas dominated by owner-occupiers often see longer tenancies and fewer voids, because tenants stay put and the rental stock turns over slowly.
Stock quality matters as much as location. A property that is cold, dated, or poorly laid out will sit empty longer than a comparable property nearby that has been maintained. Energy performance is part of this: a low rating narrows the pool of tenants willing to take the property and can affect what a landlord is permitted to let, which must be confirmed with the relevant authority for the specific property.
How to estimate void periods from listing data
Void periods can be estimated without access to a landlord's internal records. The method is to track how long individual properties stay advertised on live listings, and how often the same property reappears.
Start by recording the date each property is first seen on live listings and the date it disappears. A property that disappears quickly has likely been let; one that stays listed for weeks is either overpriced or unattractive to the local tenant pool. Repeat this across a sample of similar properties in the same area and property type.
The second signal is turnover. If the same address appears on live listings repeatedly over a two or three-year window, the tenancy is short and the void between tenancies is likely to recur. Public sale-price records can help confirm whether a property has changed hands, which sometimes explains a change in letting behaviour.
Asking rents collected from live rental listings give a useful benchmark for the local market. In our sample, the median asking rent was £800 per calendar month for one-bed properties across 35 areas, £950 for two-bed across 35 areas, £1,150 for three-bed across 23 areas, and £2,200 for four-bed across a single area. These are medians of area medians and asking prices, not achieved rents, so they should be treated as a starting point rather than a settled figure.
The cashflow impact of common void lengths
The cost of a void is not just the lost rent. It also includes the re-letting costs that fall due when a tenancy ends, and any council tax or utility liability the landlord carries while the property is empty. The exact position on council tax during a void must be confirmed with the relevant authority for the specific property.
The table below shows lost rent only, calculated from the median asking rents in our sample. It excludes re-letting costs, council tax, utilities, and any rent-free period offered to secure a tenant.
| Property type | Median asking rent (pcm) | 1-week void | 2-week void | 4-week void |
|---|---|---|---|---|
| 1-bed | £800 | ~£185 | ~£369 | ~£738 |
| 2-bed | £950 | ~£219 | ~£438 | ~£877 |
| 3-bed | £1,150 | ~£265 | ~£531 | ~£1,062 |
| 4-bed | £2,200 | ~£508 | ~£1,015 | ~£2,031 |
These figures are approximations based on the median asking rents in our sample and a 52-week year. A two-week void on a two-bed property at £950 per calendar month removes roughly £438 of rent from the year. If the same property also incurs re-letting costs, the total cashflow hit is larger than the rent figure alone suggests.
The effect on yield is straightforward. A property advertised at a rent that produces a headline gross yield will deliver less than that once voids are included. Two weeks of void on a 52-week year is roughly 3.8% of the annual rent, so a gross yield of 5% becomes closer to 4.8% before other costs. Four weeks of void removes roughly 7.7% of annual rent.
Tactics that shorten re-letting time
Reducing void length is mostly about preparation and pricing, not about marketing spend. The following measures are commonly used to shorten the gap between tenancies.
- Start marketing before the current tenancy ends. Where the tenancy agreement and notice position allow, viewings can begin while the property is still occupied, so a new tenant is lined up before the old one leaves. The notice position must be confirmed with the relevant authority for the specific property.
- Price to the local market, not to the previous rent. A property that is listed above the local median asking rent for its type and area will typically sit longer. Checking live listings for comparable stock gives a current benchmark.
- Fix the obvious defects before viewings. Damp, broken fittings, and dated kitchens and bathrooms are the most common reasons tenants reject a property that is otherwise suitable.
- Improve the energy rating where practical. A better rating widens the tenant pool and reduces the risk of the property being ruled out on running costs.
- Keep the deposit and referencing process moving. Delays between offer and move-in are a common source of extra void days, particularly where references or right-to-rent checks are slow.
- Consider the tenancy length that suits the local market. In areas with high turnover, a shorter initial term may reduce the risk of a long void later, while in stable areas a longer term reduces changeover frequency.
None of these measures removes voids entirely. They reduce the number of days a property sits empty between tenancies, which is the part of the void that can be influenced.
What to check next
Before relying on any yield figure, confirm the void assumption behind it. Check the local authority's council tax position for empty properties, since liability during a void varies and must be confirmed with the relevant authority for the specific property.
Check the energy certificate register for the property's current rating and any recommendations, and confirm with the relevant authority what rating is required for the specific letting.
Check live listings for comparable properties in the same area and property type to establish a current asking rent benchmark, and track how long those listings remain advertised to estimate a realistic void length.
Finally, recalculate the yield using the rent actually expected, not the asking rent, and subtract the estimated void weeks and re-letting costs. The resulting figure is the one that reflects the cashflow the property is likely to produce.