Home ventilation, Dorset
Positive input ventilation (PIV) in Dorset
Loft or wall units that gently push filtered air into the home to tackle condensation, across Dorset.
- From £825 inc VAT per home
- Free survey
PIV can suit Dorset houses and flats because it treats the whole home from one quiet unit.
Dorset has every kind of building, from old terraces to new estates and business parks, and every job is designed around the building in front of us, not a standard kit.
PIV in Dorset at a glance
- Area
- Dorset
- Towns listed
- 14, largest Bournemouth
- Postcode districts
- BH17, BH1, BH2, BH14, BH15 and DT3
- Price region
- South West
- Survey
- Free survey (UK mainland)
How we do it
PIV works well in houses and flats with general condensation on windows and cold walls. It does not replace extract fans: kitchens and bathrooms still need their own extract to remove steam at source. On survey we check the loft, the landing position and the existing fans, and we tell you if PIV is not the right answer.
PIV with fan upgrades
PIV plus humidity-controlled extract fans in the kitchen and bathroom for the most stubborn condensation.
Loft-mounted PIV
The most common option for houses with a loft. Usually fitted in half a day.
Heated PIV
A heater module tempers the incoming air in cold weather. Useful in homes where people feel draughts.
Guide prices in Dorset
| Work | Guide price |
|---|---|
| Positive input ventilation (PIV) loft unit, supplied and fitted (per home) | £825–£1,450 inc VAT |
| Wall-mounted PIV unit for a flat (core drilled through an outside wall) (per flat) | £1,025–£1,775 inc VAT |
| Heater module or heated PIV unit (extra over a standard unit) (extra) | £150–£305 inc VAT |
South West rates shown. Prices include VAT at 20%. The fixed price is confirmed in writing after we have seen the job.
Common reasons people call
- The house feels stuffy and damp rather than cold
- Washing dried indoors makes everything worse
- You have no loft but still need whole-flat ventilation (wall unit)
Rules in England
English building work follows Approved Document F (2021 edition) for ventilation rates, installation and commissioning. It sets extract rates for kitchens, bathrooms and utilities and asks for mechanical ventilation to be commissioned and recorded.
How the job runs
- Survey
- Fixed quote
- Install
- Set up
- Hand over
Towns we cover in Dorset
- Bournemouth
- Poole
- Weymouth
- Christchurch
- Ferndown
- Dorchester
- Wimborne Minster
- Canford Heath
- Verwood
- Portland
- Bridport
- Blandford Forum
- Swanage
- Broadstone
Questions about positive input ventilation (PIV) in Dorset
Which rules apply to ventilation in Dorset?
In England, ventilation in new and altered homes is covered by Approved Document F of the Building Regulations. Landlords also have duties under the Housing Health and Safety Rating System, and workplaces must be ventilated under the Workplace (Health, Safety and Welfare) Regulations 1992.
How long does PIV installation take?
A loft unit is normally fitted in two to four hours, including the diffuser and electrical connection.
How much does PIV cost to install?
A loft-mounted PIV unit usually costs £795 to £1,395 including VAT supplied and fitted, and £995 to £1,695 for a wall-mounted unit in a flat. A heater module adds around £145 to £295.
Which towns in Dorset do you cover?
All of Dorset, including Christchurch, Ferndown, Dorchester, Wimborne Minster and Canford Heath. If your town is not listed, send the postcode and we will confirm.
Are prices different in Dorset?
Our guide prices are adjusted by region. In Dorset we use South West rates, so positive input ventilation (PIV) loft unit, supplied and fitted is typically £825 to £1,450 inc VAT per home.
We will check the existing fans in your Dorset home at the same visit, because PIV works best with them working.
Other services in Dorset
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