Plan Review and Specification Review Perth
At Building Broker Centre, we provide plan review and specification review in Perth for homeowners who need independent checking before their plans go to builders for quoting. Plans from building designers often have errors, missing details, or vague specifications that cause expensive problems during quoting or construction.
Our role is to catch these issues before they cost you money — checking dimensions, specifications, buildability, and compliance so builders can quote accurately and you're not hit with surprises once the build starts.
Key Takeaways!
Plan review catches errors, missing details, and vague specifications before builders quote — preventing inflated contingency pricing or surprise variation costs during construction
Specification review stops cost blowouts by defining exactly what's included (stone benchtops vs laminate, tile quality, window specs) so builders quote comparable products and you know real costs
Independent plan checking identifies buildability issues, code compliance problems, and cost realism failures that designers miss — saving thousands in redesign fees and construction delays
Why Plan Review Matters Before Builder Quoting
Plan review is the quality control step most people skip. They pay a designer to draw plans, assume everything's correct because it looks professional, then send those plans to builders for quoting. That's when problems show up. Builders find missing details, unclear specifications, dimensions that don't work, or designs that don't comply with building codes. So builders either quote high to cover contingencies for all the unknowns, or they quote cheap knowing they'll slug you with variations once construction starts.
Here's what happens without proper plan review. You get three quotes from three builders. One quotes $520,000, another quotes $495,000, and the third quotes $550,000. Why the $55,000 difference? Because the plans aren't clear enough for builders to quote accurately. One builder's assumed rendered walls are included, another hasn't. One builder's included engineering for the sloping site, another's listed it as a provisional sum. One builder's spotted issues the designer missed and priced to fix them, another hasn't noticed yet and will hit you with variations later.
Plan review catches these problems before builders waste their time quoting incomplete or unclear plans. We go through plans line by line checking dimensions, specifications, buildability, and compliance. If we find issues, they get fixed before quoting starts. That means builders can quote accurately, you can compare quotes properly, and you're not dealing with expensive variations during construction because the plans were wrong from the start.
What Gets Checked During Plan Review
Plan review isn't just glancing at drawings to see if they look nice. It's systematic checking of everything that affects whether builders can actually build what's drawn and whether the cost matches your budget.
Dimensional accuracy and consistency
Are dimensions correct and do they match between different drawings? Floor plans show one measurement, elevations show another, and structural drawings show something different. These inconsistencies cause problems during construction when trades realize things don't line up. We check that dimensions are consistent across all drawings and that room sizes are realistic, not squeezed to make the overall home look bigger on paper than it actually is.
Completeness of drawings
Are all required details actually shown? Window and door schedules incomplete. Roof framing not detailed properly. Bathroom layouts missing fixture locations. Kitchen elevation not showing where appliances go. Electrical and plumbing rough-ins not marked. These missing details mean builders have to guess, and their guesses get expensive when they're trying to cover risk.
Code compliance and council requirements
Does the design meet current building codes and local council requirements? Ceiling heights too low in some areas. Setbacks wrong for the zone. Stormwater drainage not detailed properly. Bushfire Attack Level requirements not addressed if the site needs them. Energy efficiency ratings calculated incorrectly. These compliance failures delay approvals or require expensive redesigns once council rejects the plans.
Buildability and construction logic
Can Perth residential builders actually construct this design efficiently? Roof structures that are unnecessarily complex. Wall framing that doesn't align with standard practices. Windows specified in sizes that aren't readily available. Details that look good on paper but are impractical or expensive to build. We check that designs suit how Perth builders actually construct homes, not just how designers think they should be built.
The Specification Review Problem
Specification review is even more important than plan review because this is where cost blowouts hide. Plans show what gets built. Specifications define what quality and what products. If specifications are vague or incomplete, every builder interprets them differently and your quotes become meaningless.
I've seen this dozens of times. Plans show "stone benchtops to kitchen and bathrooms." But the specification doesn't say what stone. Is it laminate trying to look like stone? Engineered stone? Natural stone? Those three options have completely different costs. One builder quotes $8,000 for laminate. Another quotes $15,000 for engineered stone. The third quotes $22,000 for natural stone. You can't compare quotes because the specification was too vague to define what's actually being priced.
The same problem happens with flooring, tiles, fixtures, external finishes, windows, roofing — anything where quality and product selection affects cost. If the specification says "tiles as per allowance" but doesn't define tile quality, size, or where they're used, builders make assumptions and quote differently. Then you're stuck choosing between quotes that aren't actually comparable because they're pricing different products.
Specification review means going through every specification and making sure it's detailed enough that builders know exactly what they're quoting. What brand or quality level? What size or dimension? What color or finish? What areas does it apply to? When specifications are clear and complete, builders quote the same products and you can actually compare pricing properly.
Real Examples of Plan and Specification Problems
Here's a real example from a project in Joondanna. The designer created beautiful plans with large sliding doors across the entire back of the house opening to the alfresco. Looked amazing on the drawings. Problem was, the specification didn't detail which doors. The designer had just written "sliding doors as per plan." One builder quoted standard aluminum sliders at $8,000. Another builder quoted high-performance commercial grade sliders at $18,000 because that's what the span required for structural reasons. The clients had no idea there was a $10,000 difference hiding in the vague specification until quotes came back.
Another example from a project in Duncraig. Plans showed a beautiful outdoor kitchen in the alfresco area. Looked fantastic. But the specification never said what was included in "outdoor kitchen." One builder quoted $6,000 for basic cabinetry only. Another quoted $15,000 including sink and plumbing. A third quoted $25,000 with sink, plumbing, BBQ, and stone benchtops. Three completely different interpretations of the same vague specification. The clients couldn't compare quotes because they didn't know what each builder had actually priced.
I've also seen plans where ceiling heights varied randomly throughout the home because the designer wasn't paying attention. Main living area showed 2.7m ceilings. Bedrooms showed 2.4m. Kitchen showed 2.55m. Builders spotted the inconsistency and either quoted to fix it (expensive) or quoted assuming the cheapest option (2.4m throughout) which wasn't what the clients wanted. Plan review catches these problems before builders quote so the design is consistent and matches what you actually want.
Cost Realism and Budget Alignment
Plan and specification review also checks cost realism. Are the specifications and design details aligned with your budget, or has the designer spec'd things that will blow your budget without telling you?
Designers sometimes spec high-end products because they look good in their portfolio or because they're used to working with clients who have bigger budgets. They'll specify commercial grade windows, premium stone throughout, high-end fixtures, complex roof lines, and expensive external finishes without checking if your budget can actually support those choices. You don't find out until builders quote and every quote comes back $80,000-$100,000 over budget.
Plan review catches this early. We look at what's been specified and compare it to your stated budget. If the designer's spec'd $150,000 worth of finishes but your budget only allows $100,000, we flag it before plans go to builders. That saves you from getting quotes you can't afford and having to go back to the designer for a complete specification downgrade, which delays your timeline and costs extra design fees.
Cost realism also means checking that construction details match what Perth builders can deliver efficiently. Unnecessarily complex details that add cost without adding value. Structural elements that require expensive engineering when simpler solutions would work. Site preparation work that hasn't been properly estimated. These cost realism failures get caught during plan review so your budget expectations match what you're actually going to pay.
Engineering and Site-Specific Issues
Plan review also identifies engineering and site-specific issues that designers either miss or don't properly address in their drawings. This is particularly important for sites with challenges — slopes, poor soil, tight access, or unusual constraints.
A sloping site in areas like Scarborough or Sorrento requires proper retaining wall details, drainage design, and structural calculations for split-level construction. If the designer hasn't detailed these properly, builders either won't quote the job or they'll include massive provisional sums to cover unknowns. Plan review catches missing engineering details before quoting so the builder knows exactly what's required and can price accurately.
The same applies to soil conditions. Some areas of Perth have reactive clay soils that require specific footing design. Some sites have high water tables that need special consideration for drainage and moisture protection. Some sites have contamination or fill that affects foundation design. If the designer hasn't addressed these site-specific issues in the plans, builders can't quote properly. Plan review identifies what's missing so you can get proper engineering advice before builders quote.
Site access is another common issue that plan review catches. Narrow blocks in suburbs like Doubleview or Morley where construction equipment can't easily access the site. Restricted working hours in certain areas. Neighboring properties that limit where materials can be stored or where scaffolding can be erected. These access constraints affect construction costs, but if they're not identified and documented in the plans, builders either miss them in quoting or price high to cover risk.
The Plan Review Process and Timeline
Plan review typically takes 3-5 business days depending on complexity. Simple single-storey homes on flat sites are faster to review than complex two-storey homes on sloping sites with detailed specifications.
We start by reviewing architectural plans for completeness, accuracy, and buildability. Are all required drawings included? Do dimensions match across different plans? Are details shown clearly enough that builders can price accurately? Are there any obvious design issues that will cause construction problems?
Then we review specifications document by document. Kitchen specifications, bathroom specifications, flooring specifications, external finishes, windows and doors, fixtures and fittings. For each item, we check that quality levels are defined, products are clearly specified, and allowances are realistic for what you want.
The cost for plan and specification review ranges from $800-$1,500 depending on project size and complexity. But that cost saves you far more when it prevents builder contingencies, variation surprises, or expensive redesigns because problems weren't caught before quoting started.
When Plan Review Saves the Most Money
Plan review saves the most money in three situations. First, when you're using a designer who doesn't have much experience with residential builders and practical construction. Their plans might look great but be impractical or expensive to build. Plan review catches buildability problems before builders quote inflated prices to cover construction difficulties.
Second, when you've got a challenging site — slope, narrow lot, poor access, difficult soil conditions. Plans for challenging sites need to be detailed and specific about how construction challenges will be addressed. If those details are missing or vague, builders quote high or won't quote at all. Plan review identifies what's missing so you can get proper engineering and documentation before quoting.
Third, when you're working with a tight budget and can't afford specification surprises during quoting. If your budget is $550,000 and every quote comes back at $620,000 because specifications were unrealistic, you've wasted weeks getting quotes you can't use. Plan review aligns specifications with budget before quoting starts so quotes come back in a range you can actually work with.
Need plan review and specification review before your Perth plans go to builders?
Call Frank on 0489 088 527 for independent checking that catches errors and saves money.
