Solar Estimating and Takeoff Services

We quantify solar installations from your drawings — modules and racking by count and attachment, inverters and balance of system by unit, DC and AC conductor runs by measured length, and the interconnection and structural work as their own scope — delivered as an editable Excel workbook.

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What We Take Off

A dollars-per-watt figure is a sales tool, not a takeoff. What decides the cost of an installation is everything other than the modules: how the array attaches to the roof or the ground, whether the structure can carry it, how far the conductors run, what the interconnection requires, and what the utility and the authority having jurisdiction are going to demand before it energises. The modules are the most predictable line in the package.

Modulescounted by unit with wattage, dimensions and weight, plus the spare and breakage allowance the specification or the supplier requires

Racking and mountingby attachment point and by rail length, separating ballasted, mechanically attached, penetrating, standing seam clamp, ground mount and carport systems, which differ enormously in cost and in structural implication

Roof attachments and flashingcounted individually with the flashing assembly each penetration requires, since every penetration through a roof is a potential leak and a roofing warranty question

Ballastby weight and distribution where a ballasted system is used, which is a structural load question before it is a material one

Structural modificationreinforcement where the existing structure cannot carry the array, quantified against the structural assessment rather than assumed unnecessary

Inverterscounted by unit and type, separating string inverters, central inverters and microinverters, with their mounting, disconnects and clearances

DC systemmodule-level electronics, combiner boxes, DC disconnects, and conductor runs measured on the actual routed path with conduit by size and length

AC systeminverter output circuits, AC combiners, disconnects, metering and the run to the point of interconnection, measured routed rather than plan-flat

Conduit, raceway and cable managementby linear foot and size with support spacing, plus the wire management the module-level wiring requires

Grounding and bondingequipment grounding conductors, module bonding, grounding electrode system and any lightning protection interface

Rapid shutdown and code compliance equipmentrequired by current code and quantified as its own scope, since it is equipment and labor rather than a compliance formality

Point of interconnectionthe service equipment work, whether a line-side tap, a supply-side connection, a breaker addition or a service upgrade, which is frequently the single largest variable in a solar estimate

Utility interconnection requirementsthe utility-side work, metering, protection, studies and any required equipment, along with the application and approval process duration

Monitoring and communicationsmonitoring hardware, data connection, gateways and commissioning of the monitoring platform

Energy storage interfacewhere batteries are included, the enclosure, disconnects, protection, clearances and the code requirements for the installation location

Structural and roof assessmentwhere an existing roof carries the array, its condition and remaining life, since installing over a roof near end of life is a scope decision with real consequences

Access, staging and safetyroof access, fall protection, material hoisting and, on ground mount, site access and foundation work

Permitting, inspection and commissioningbuilding and electrical permits, utility approval, inspection, testing and commissioning, each with duration as well as cost

How Solar Quantities Are Measured

Every quantity below is reported in the unit the scope is actually bought and bid in — not converted into a single convenient unit that hides where the cost sits.

ModulesEA by wattageCounted with wattage and weight. Weight matters as much as wattage on a retrofit roof.

Rackingattachment points EA and rail LFBy attachment and rail, not by array area. Attachment spacing is a wind and structural answer.

Roof attachmentsEA with flashingEach penetration counted with its flashing assembly. Every one is a potential leak and a warranty question.

BallastLBS and distributionA structural load question before a material one, with distribution across the roof stated.

InvertersEA by type and ratingString, central and microinverters counted by unit with mounting and disconnects.

DC conductorsLF on routed pathMeasured on the actual route, not plan-flat. Vertical runs and routing around obstructions are real length.

AC conductorsLF by size on routed pathIncluding the run to the point of interconnection, which can be the longest run on the job.

ConduitLF by size with supportsBy diameter with support spacing, which is a real hardware count on a long roof run.

Rapid shutdown equipmentEARequired by current code, quantified as equipment and labor rather than as a compliance line.

Point of interconnectionby scopeLine-side tap, breaker addition or service upgrade — frequently the single largest variable in the estimate.

Structural modificationby elementAgainst the structural assessment. Assuming none is needed is assuming a result nobody has produced.

Commissioningby systemTesting, utility witness and monitoring commissioning, each with duration as well as cost.

Who This Is For

General contractors carrying this trade directly, or checking a subcontractor's number before it goes into the bid.

Subcontractors pricing their own scope in this division.

Developers and owners validating a number they've already been given.

Material suppliers and distributors verifying a customer's order.

What You Receive

An itemized Excel takeoff, organized by division
A marked-up plan set — every quantity traces back to a location on the drawings
Labor, material and equipment split out separately
Waste and overage factors shown as visible line items
An assumptions and exclusions schedule

Marked-up solar plan crop

What Moves the Number on Solar

The point of interconnection. How the array connects to the existing electrical service is frequently the largest single variable in a solar estimate and it has nothing to do with the array. A simple breaker addition in an existing panel with capacity, a line-side tap, and a full service upgrade with utility coordination are three wildly different numbers, and which applies depends on the existing service capacity and the utility's rules rather than on the system size.

Structural capacity. An array is dead load, and a ballasted array is a lot of dead load concentrated where the ballast sits. Whether the existing structure can carry it is a structural engineering answer, and where it cannot, reinforcement is a scope that can exceed the solar installation. An estimate that assumes no structural work has assumed a result nobody has produced.

Attachment method. Ballasted, penetrating, standing-seam clamp and ground mount differ in material, in labor, in structural implication and in roofing risk. Attachment spacing is set by wind uplift, so a high-wind site needs more attachments than a sheltered one for the same array, and each penetration carries a flashing detail.

Roof condition and remaining life. Installing an array over a roof with five years left means removing and reinstalling the array to re-roof, which is a cost the owner will meet whether or not anyone estimated it. Where the roof is near end of life, re-roofing first is the honest recommendation, and the assessment belongs in the estimate assumptions either way.

Conductor routing distance. The run from the array to the inverters and from the inverters to the point of interconnection is measured on the actual route, including vertical runs and routing around obstructions. On a large roof with a service entrance at the far corner, that distance and its conduit, supports and voltage drop considerations is a substantial line.

Code compliance equipment. Rapid shutdown, fire access pathways and setbacks, labelling and disconnecting means are current code requirements with equipment and labor attached. Fire setbacks also reduce usable roof area, which means a roof that looks large enough may not fit the array the system size assumes.

Permitting, utility approval and duration. A solar project needs a building permit, an electrical permit, a utility interconnection application and approval, inspection and commissioning. The utility process in particular runs on its own timeline regardless of the construction schedule, and a project cannot energise until it completes. That is a duration risk as much as a cost.

What We Need From You

A complete set is ideal, but rarely what exists. Send what you have — we will tell you at quote stage what can be quantified firm and what has to be an allowance.

Site plan and roof plan with the array layout
Module and inverter specifications or cut sheets
Racking system and attachment details
Single-line diagram showing DC and AC configuration and the point of interconnection
Existing electrical service information — size, available capacity and panel schedules
Structural drawings and any structural assessment of the supporting roof or ground conditions
Roof assembly information and its age and condition, plus any existing roofing warranty
Wind and snow design criteria for the site
Utility interconnection requirements and any completed application or study
Local fire code access pathway and setback requirements

How It Works

1 Send your plans — PDF, DWG, DOC, images or ZIP, up to 100MB per file.
2 Get your quote — a flat price for the scope with a delivery date, confirmed in writing.
3 Approve — nothing starts until you confirm.
4 We take it off — quantities from the drawings and schedules.
5 Delivery — workbook, marked-up set, assumptions schedule.

How Pricing and Turnaround Work

Every project is priced individually from your drawings. Send the plan set and you get a flat quote for the scope before any work starts — no hourly billing, no open-ended engagement.

Turnaround depends on the size of the package and how many trades are in scope — which is why you get a firm delivery date with your quote rather than a generic promise.

Tools and Standards

Takeoffs are produced in Bluebeam, PlanSwift, Trimble, STACK, organized against CSI MasterFormat divisions — this scope is specified under Division 48 — Electrical Power Generation (48 14 00 Solar Energy Electrical Power Generation Equipment).

Quantities and assemblies are read against the published standards that govern this trade, because the standard is what decides whether two apparently identical items are actually the same line item:

NEC Article 690 — solar photovoltaic systems, including rapid shutdown requirements
NEC Article 705 — interconnected electric power production sources, which governs the point of interconnection
NEC Article 706 — energy storage systems, where batteries are included
UL 1703 / UL 61730 — photovoltaic module safety standards
UL 1741 — inverters, converters and interconnection system equipment
ASCE 7 — wind and snow load provisions, which govern array attachment and ballast
IFC and local fire code requirements for roof access pathways and setbacks

Pricing is built on RSMeans cost data localized to your project's market, then reconciled against current supplier quotes and our own completed project costs. Every estimate states its pricing basis and the date it was priced.

Why Solar Is Estimated Wrong

Priced at dollars per watt. A per-watt figure averages across roof types, attachment methods, conductor distances, structural conditions and interconnection scopes that vary by multiples between projects. It is a useful benchmark and a poor estimate, and it is systematically wrong on exactly the projects that differ from the average.

Interconnection scope assumed simple. The gap between a breaker addition into an existing panel with spare capacity and a full service upgrade with utility coordination is enormous, and it depends on the existing service rather than on the array. Assuming the easy case is assuming away the largest variable in the package.

Structural capacity assumed adequate. An array is permanent dead load, and ballasted systems concentrate it. Where the structure cannot carry it, reinforcement can exceed the cost of the solar installation. This is a structural engineering answer and an estimate that does not state the assumption has quietly taken the risk.

Conductor runs measured plan-flat. DC and AC runs go up, over, around and down, and the plan distance understates the actual route substantially. On a large roof with a distant service entrance this is a large quantity of conductor, conduit and supports, plus a voltage drop consideration that can force a larger conductor size.

Roof penetration flashing not counted. Every attachment through a membrane is a flashing detail and a question about the existing roofing warranty. Counted individually they are predictable; absorbed into a racking rate they disappear, and the warranty question never gets asked at all.

Fire setbacks reducing usable area. Code-required access pathways and setbacks remove roof area from the array. A roof that appears large enough for the target system size may not be once the setbacks are applied, which makes this a design issue discovered at permit review rather than at estimate stage.

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Frequently Asked Questions

Do you price solar by dollars per watt?

No. A per-watt figure averages across roof types, attachment methods, conductor distances, structural conditions and interconnection scopes that vary by multiples between projects. We quantify each of those separately, because they are what actually decides the cost — the modules are the most predictable line in the package.

Do you include the point of interconnection?

Yes, and we treat it as the major variable it usually is. A breaker addition into a panel with spare capacity, a line-side tap and a full service upgrade with utility coordination are three very different numbers, decided by the existing service and the utility's rules rather than by the array size.

Do you account for structural capacity?

Yes, against the structural assessment where one exists. An array is permanent dead load and ballasted systems concentrate it, so where reinforcement is required it can exceed the solar installation itself. Where no assessment exists, we state that assumption on the face of the estimate rather than assuming the favourable answer.

How do you measure conductor runs?

On the actual routed path including vertical runs and routing around obstructions, not plan-flat. On a large roof with a distant service entrance this is a substantial quantity of conductor, conduit and supports, and the voltage drop over that distance can force a larger conductor size.

Do you count roof penetrations and flashing?

Yes, every attachment individually with its flashing assembly. Each one is a potential leak and a question about the existing roofing warranty, and both disappear when penetrations are absorbed into a racking rate.

Do you include permitting and utility approval?

Yes, as cost and as duration. Building permit, electrical permit, utility interconnection application and approval, inspection and commissioning all apply, and the utility process runs on its own timeline regardless of the construction schedule. A system cannot energise until that completes, which makes it a schedule risk as much as a cost line.

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