Void periods: the cheapest time to get to EPC C

Ask a builder when they’d rather insulate the walls of a one-bed flat — with a tenant’s furniture in it, or empty — and you’ll get a short answer. The void period is the natural moment for EPC works. What’s less obvious is how much money the timing decision moves, and how few voids most landlords actually have left before 2030.

The lost-rent maths

Take a London flat letting at £2,000 a month and internal wall insulation needing roughly two weeks of intrusive access.

Done mid-tenancy (if the tenant even consents): negotiated access, works slowed by the furniture and the goodwill budget, often a rent reduction for the disruption — and a strained renewal conversation later.

Done outside a void, by breaking a tenancy for it: two weeks of works becomes a month of vacancy with marketing time either side. Call it £2,000–£4,000 of lost rent stacked on top of the build cost.

Done inside a natural void: the property was going to be empty anyway. Works run in parallel with the between-tenancy clean, the reference checks, and the marketing photos happen after the dust settles. Lost rent attributable to the EPC works: at or near zero.

Same works, same invoice from the builder — a four-figure difference in total cost, decided purely by calendar position.

The squeeze nobody prices in

Every landlord with a D-rated property is looking at the same deadline. The closer 2030 gets, the more the retrofit trades — insulation crews above all — become the bottleneck. Waiting doesn’t just risk lost rent; it means buying labour in the most expensive year in the sector’s history, at 2029 prices, on 2029 lead times. The landlords who move at their 2026–2028 voids buy the same works in a buyer’s market.

Three voids, maybe two

The average tenancy runs one to three years. Between now and October 2030, a typical property will be vacant perhaps two or three times — sometimes once. Each void that passes without the works removes an option, until the only slot left is the panic slot.

This is why “we’ll deal with it nearer the time” is the expensive strategy, even though it feels like the cautious one.

The forward void schedule

The fix is boring and effective: a forward void schedule. For each property in a portfolio — a landlord’s three flats or an agent’s three hundred — map:

• current EPC rating and certificate expiry,
• what the property needs to reach C, costed,
• the tenancy end date, i.e. the next natural works window.

Sequence those and the 2030 cliff turns into an ordinary maintenance plan: this year’s voids, next year’s voids, done by 2028 with room to spare.

Building that schedule is exactly what we do — free, from your property list, mapped to your tenancy dates, and (for agents) branded as yours. Book the free assessment or see how the whole pipeline works.

My EPC Partner maps portfolios against these rules for free — every property's rating, expiry, and route to C, scheduled to your voids. Book the free assessment.