Is this the project you want cost guidance for?
Many people start with fittings, finishes or furniture. This tool starts one step earlier: what preparation, investigation and trade work may be needed before those products can be installed?
What this page is for
This page is a general planning guide. It helps you identify whether your idea is still at the thinking stage, whether it needs more investigation, or whether it may be ready to move into a structured planning workflow.
What this page is not
It is not a quotation, DIY instruction, engineering advice, consent advice or a substitute for inspection by a builder, electrician, plumber, designer, engineer, council or other suitable professional.
Important principle
Actual pricing by tradespeople may differ materially because they will identify factors the app cannot know without inspection. The app helps with early thinking, preparation, risk awareness and order-of-magnitude budgeting.
What you can do at no charge
The free level is designed to help users recognise whether their project needs more structured planning before money is spent on products or prices are sought from trades.
Free access includes
- Project type selection
- Early red flag prompts
- Consent trigger awareness
- Research and planning links
- Builder-friendly guidance
- Project readiness prompts
Why start with free access?
The first question is not “what will it cost?” It is “what exactly is the project we are trying to cost?” That needs to be considered before fittings, products and finishes drive the conversation.
Next step
When the user is ready, the next stage is initial planning: a guided checklist that helps confirm whether this is the project they want indicative cost guidance for.
Internal non-load-bearing wall
A common lower-complexity project, provided the wall is genuinely non-structural and not bracing, fire-rated or service-heavy.
Planning questions
- Is the wall definitely non-load-bearing?
- Could it be a bracing element?
- Are there pipes, wiring or data cables in the wall or ceiling/floor path?
- Will skirtings, stopping, painting or flooring repairs be needed?
- Will access or travel affect cost?
Consent / professional trigger awareness
Constructing, altering or removing an internal wall may be simpler when the wall is not load-bearing, not bracing, not a fire separation wall, not part of a specified system and not bonded masonry. If uncertain, professional confirmation is recommended before relying on a budget.
Preparation costs commonly forgotten
- Service checks
- Framing, fixings and linings
- Stopping and sanding
- Painting
- Skirting or trim changes
- Waste removal
Internal load-bearing wall
This moves from simple refurbishment into structural territory and normally needs specialist input before reliable budgeting.
Planning questions
- What is above the wall?
- Does it support roof, ceiling or floor loads?
- Is temporary propping required?
- Will a beam, lintel or posts be needed?
- Will flooring, ceiling, wall linings or services be affected?
Professional trigger awareness
Structural changes can materially change cost, timing and consent requirements. A builder, designer or engineer may need to confirm loads, supports and whether consent is required.
Cost surprise areas
- Engineering/design input
- Temporary propping
- Beam and post installation
- Ceiling and floor repairs
- Electrical or plumbing relocation
- Consent-related costs
Kitchen replacement and appliance repositioning
Kitchen product costs are only part of the story. Relocation of appliances, plumbing and electrical services can turn a simple replacement into a more involved project.
Planning questions
- Are sink, dishwasher, oven, hob or rangehood positions changing?
- Will walls, flooring or ceiling linings need repair after removal?
- Is the switchboard or existing wiring suitable for new appliance loads?
- Are lights dimming when major appliances operate?
- Will ventilation or extraction need upgrading?
Professional trigger awareness
New wiring, plumbing relocation, extraction changes or structural alterations may require licensed trades and may affect compliance. Older homes can involve additional investigation before cost guidance is reliable.
Preparation costs commonly forgotten
- Removal and disposal of old cabinetry
- Wall repairs and stopping
- Flooring repairs under old units
- Electrical upgrades
- Plumbing adjustments
- Painting and finishing
Bathroom renovation with new shower
Bathrooms often create the biggest difference between product cost and real project cost because waterproofing, plumbing, rot and ventilation matter.
Planning questions
- Is the shower staying in the same location?
- Is the floor soft, bouncy or stained?
- Is there visible mould, damp smell or previous leaking?
- Will wall or floor linings need replacement?
- Is ventilation adequate?
Professional trigger awareness
Wet area changes may require consent or professional input, especially where waterproofing, drainage or layout changes are involved. Rotten framing or flooring can significantly change the scope.
Preparation costs commonly forgotten
- Demolition and disposal
- Subfloor or framing repairs
- Waterproofing systems
- Plumbing changes
- Ventilation upgrades
- Stopping, painting and finishing
New loo
Adding a toilet is often more than a small fixture purchase. Drainage, venting and wastewater capacity can dominate cost.
Planning questions
- Where is the nearest existing waste pipe?
- Is the property on mains sewer or septic?
- If septic, is the system old or near capacity?
- Is there suitable fall for drainage?
- Is ventilation available?
Professional trigger awareness
Adding sanitary fixtures commonly requires plumbing/drainage assessment and may require consent. Older septic systems can create major project consequences.
Cost surprise areas
- Drainage route
- Floor cutting or reinstatement
- Ventilation
- Septic upgrades
- Council or compliance requirements
New bathroom with loo
A new bathroom combines wet-area construction, additional sanitary fixtures, ventilation, plumbing, drainage and finishing.
Planning questions
- Is this a new wet area or a conversion of an existing room?
- How far away are existing plumbing and drainage services?
- Is there access under the floor or through ceiling space?
- Is the home on septic?
- Are external walls or windows affected?
Professional trigger awareness
A new bathroom with toilet will generally need significant professional input. Consent, waterproofing, plumbing, drainage, ventilation and wastewater capacity should be considered before budgeting too tightly.
Preparation costs commonly forgotten
- Framing and lining
- Waterproofing
- Drainage and plumbing
- Electrical and lighting
- Ventilation
- Flooring and finishing
External wall changes
External walls affect weather protection, structure, cladding, insulation and openings. They are rarely just a cosmetic issue.
Planning questions
- Are new doors or windows being added?
- Is cladding being removed or changed?
- Will flashing or weatherproofing be affected?
- Is insulation being added or upgraded?
- Is there any sign of moisture damage?
Professional trigger awareness
External wall changes can trigger weathertightness, structural and consent issues. Specialist advice should be sought where openings, cladding or structure are affected.
Cost surprise areas
- Hidden rot
- Flashing details
- Cladding compatibility
- Insulation continuity
- Painting and finishing
- Scaffolding or access
Roofing and reroofing
Roofing work may look straightforward from the outside, but structure, loading, pitch, flashing and access can change the project significantly.
Planning questions
- Is it like-for-like replacement?
- Is the roofing material changing?
- Is the roof profile, pitch or structure changing?
- Are there leaks, sagging or rotten timbers?
- Will scaffolding or edge protection be required?
Professional trigger awareness
Changing roof weight, structure, pitch or form can require specialist assessment and may require consent. Even like-for-like reroofing should be checked against current requirements and council practice.
Cost surprise areas
- Access and safety systems
- Rotten framing
- Flashing replacement
- Spouting and downpipes
- Insulation opportunities
- Disposal of old roofing
Replacement or installation of fire box
Solid fuel heaters involve fire safety, flues, clearances, hearths and local requirements.
Planning questions
- Is this a replacement or new installation?
- Is the existing flue suitable?
- Are hearth and clearance requirements met?
- Will roof penetration work be needed?
- Are local clean-air or appliance rules relevant?
Professional trigger awareness
Installing, moving or replacing a solid fuel heater usually needs building consent and installation by someone familiar with the appliance and current requirements.
Cost surprise areas
- Flue upgrades
- Roof penetration and flashing
- Hearth work
- Wall/ceiling repairs
- Consent and inspection steps
Removal of inner wall
People often ask about removing a wall before knowing whether it is structural, bracing, fire-rated or carrying services.
Planning questions
- Is the wall load-bearing?
- Is it part of bracing?
- Are there services inside?
- Will flooring, ceiling or adjacent walls need repair?
- What finish standard is expected afterwards?
Professional trigger awareness
If the wall is structural, bracing-related, fire-rated or service-heavy, the project may need professional design, consent or licensed trades before cost guidance is reliable.
Cost surprise areas
- Structural support
- Electrical relocation
- Ceiling repairs
- Floor patching
- Stopping and painting
New floor for house on piles
Floor replacement ranges from simple coverings to structural work involving joists, bearers, piles, bracing and moisture.
Planning questions
- Is this floor covering, subfloor repair or structural floor replacement?
- Does the floor bounce if you jump on it?
- Are there squeaks, slopes or soft spots?
- Is there underfloor access?
- Is there dampness or poor ventilation under the house?
Professional trigger awareness
Structural floor repairs or replacements can require professional assessment. Older houses on piles may have moisture, bracing or pile-condition issues that materially affect scope.
Cost surprise areas
- Rotten joists or bearers
- Pile condition
- Subfloor ventilation
- Insulation opportunity
- Access difficulty
- Floor level correction
Dormer loft
Dormers and loft conversions are major alterations, not simple fit-outs.
Planning questions
- Is the space intended to become habitable?
- Will roof structure or profile change?
- How will weatherproofing be detailed?
- Are stairs, access and escape issues relevant?
- Will insulation, ventilation and fire requirements be affected?
Professional trigger awareness
A dormer loft will almost always need professional design and consent. Structural, weatherproofing, insulation, access and fire considerations should be assessed early.
Cost surprise areas
- Engineering and design
- Roof structural changes
- Flashing complexity
- Scaffolding
- Stairs/access
- Interior finishing
Room under a house on a slope
This can involve structure, excavation, retaining, drainage, moisture protection, access and habitability.
Planning questions
- Is excavation required?
- Are retaining walls involved?
- Is the area dry and well drained?
- Is the space intended to be habitable?
- Are structural supports being changed or enclosed?
Professional trigger awareness
Creating a room under a house on a slope commonly requires professional design, drainage assessment and consent. It should be treated as a full alteration project.
Cost surprise areas
- Excavation
- Retaining and drainage
- Moisture protection
- Structural support
- Access and stairs
- Services and ventilation