TL;DR
Get business pricing on tools and workshop supplies
- Business-only prices and quantity discounts
- Tax-exempt purchasing
- Multiple users, one account, clear invoices
A Livingetc report, drawing on advice from bathroom designers and plumbing professionals, says poor ventilation can allow moisture to contribute to condensation, mold and damage to bathroom finishes. The experts recommend planning mechanical extraction early, including in bathrooms with windows, but the source does not provide fan specifications or a full account of applicable building rules.
A Livingetc report featuring bathroom designers and plumbing professionals warns that inadequate extraction can let moisture build up, contributing to condensation, mold and damage to finishes over time. The experts recommend treating ventilation as part of bathroom design from the outset, rather than leaving the fan until after layout and finishes have been decided.
Bathrooms produce moisture through showers and baths. If humid air is not removed effectively, the report says, water vapor can condense on surfaces and contribute to damp, mold and mildew, as well as peeling paint and deteriorating finishes. These problems can affect cabinetry, wall treatments and other materials, potentially adding repair work after a renovation.
The professionals interviewed argue that an opening window is not always a substitute for mechanical extraction. A window may help air a room, but the report says it may not clear steam quickly, particularly during hot showers or in winter, when occupants may be less willing to leave it open. Its cited advice treats a separate toilet room differently from a bathroom with a bath or shower.
Planning ahead can also affect how neatly a fan is installed. The report recommends considering fan location, ducting and wiring alongside lighting and joinery, before ceilings are closed and tiling begins. Retrofitting is possible, but the amount of disruption depends on the room: an outside wall may offer easier access than an internal bathroom, where opening a ceiling or adding discreet boxing may be needed.
Moisture Can Put Finishes at Risk
The practical concern is not just fogged mirrors. Persistent moisture can contribute to mold, damp and deterioration, and may affect costly materials such as natural stone, timber cabinetry and specialist wall finishes. The report’s contributors say adequate extraction helps protect those investments, though the source does not quantify how often such damage occurs or how much repairs typically cost.
Ventilation choices also influence a project’s layout and finish. Duct routes, wiring and fan placement are easier to account for before construction is complete. Leaving those decisions late can limit options for a discreet installation and may mean extra work to access ceilings or walls. That makes extraction a design and maintenance issue, not simply a final fixture selection.
The advice is relevant to people planning a new bathroom or a major refurbishment. It does not mean every bathroom will develop mold without a fan: outcomes depend on the room, how it is used and how moisture is managed. But the experts say relying on a window alone can leave some bath and shower rooms without enough ventilation.
Products Worth Considering

Philips Hue Secure Starter Kit with Contact Sensors, Motion Sensor, Bridge, and Color Smart Bulbs

Google Nest Learning Thermostat (4th Gen) with Nest Temperature Sensor (2nd Gen), Obsidian

Ring Alarm 14-Piece Kit
As an affiliate, we earn on qualifying purchases.
Plan Fans Before Finishing Work
The Livingetc report presents advice from professionals including Arezoo Pouya, a design and sales consultant at West One Bathrooms; Manuela Hamilford, creative director of Hamilford Design; and plumbing and design specialists working on bathroom projects. Their shared recommendation is to address extraction during the early design stages, when the placement of ducts and cables can be coordinated with other work.
The report also describes a system used in one internal bathroom designed by Levan House Design: a fan that runs continuously at low speed and responds to humidity by increasing its operation when someone showers or takes a bath. This is an example cited by the designers, not a universal specification or a claim that every bathroom requires the same setup.
For new builds and complete renovations, the report quotes a design consultant saying building regulations require a fan regardless of whether a window is present. Exact requirements can depend on location and project details; the article advises readers to check the regulations that apply where they are carrying out work.
““Condensation leads to mold and damp, and fixing that once the bathroom is finished costs far more than planning it properly from the start.””
— Arezoo Pouya, design and sales consultant at West One Bathrooms
Fan Requirements Vary by Project
The supplied report does not give a publication date, fan-capacity calculations, product recommendations or a complete technical guide to choosing equipment. It also does not set out the building regulations in specific jurisdictions, so its general statement about requirements should not replace checking local rules for a particular project.
The source does not quantify the likelihood, timeline or cost of damage from poor ventilation. It describes possible consequences and quotes professionals’ experience, rather than reporting a controlled study or a measured rate of bathroom failures. The degree of risk will vary with the room, its ventilation, materials and use.
It is also not clear from the report which fan type or operating arrangement is appropriate for every bathroom. It mentions a continuously running, humidity-sensing system as one design example, but does not provide enough detail to make that a blanket recommendation. A suitable system and installation method require project-specific assessment.
Check Local Rules Before Work
Homeowners planning a new bathroom or renovation should discuss extraction, duct routes and fan placement with the relevant design and installation professionals before ceilings are closed or tiles are fitted. The report advises checking local building regulations to confirm what is required for the project.
For an existing bathroom, the next step is to establish whether the current fan is present and functioning and whether an upgrade is needed. The supplied article does not give a diagnostic checklist or installation instructions. Fan selection, electrical work and ducting should be assessed and carried out by appropriately qualified professionals in line with applicable safety and building requirements.
Key Questions
Can an open bathroom window replace an extractor fan?
The report’s contributors say a window may not clear shower or bath steam quickly enough, especially in winter. They recommend mechanical extraction for bathrooms with a bath or shower; local rules may also set requirements.
What damage can poor bathroom ventilation contribute to?
The report lists condensation, damp, mold and mildew, along with peeling paint and damage to finishes. It also cites concerns about timber cabinetry and other materials, but does not quantify the risk or repair costs.
When should an extractor fan be planned?
The interviewed professionals recommend including ventilation during the early design and layout stages, before ceiling work and tiling. That allows ducting, wiring and fan placement to be coordinated with the rest of the renovation.
Do building rules require a bathroom fan?
The report quotes a consultant who says fans are required in new builds and complete renovations even when a window is present. Requirements vary by jurisdiction and project, so check the rules that apply locally.
Can an extractor fan be added after a bathroom is finished?
Yes, the report says retrofitting is possible, but disruption depends on access. A bathroom beside an outside wall may be easier to work on than an internal room, where a ceiling may need to be opened or boxed in.
Source: livingetc.com
