Low Voltage Estimating Software
Low voltage estimating software counts data, security, fire alarm and AV devices on the drawings and prices the cable, pathway, terminations and labor behind each one. Low-voltage estimating is count-heavy: data drops, cameras, card readers, speakers, smoke detectors, pull stations. Each device drives cable, pathway, terminations and testing. SparkQuote counts the devices on your Division 27 and 28 drawings and builds the cable and labor from there.
What SparkQuote counts
| System | Typical items |
|---|---|
| Structured cabling | Data/voice outlets by port count, wireless access points, racks, patch panels |
| Security and access control | Cameras, card readers, door contacts, REX devices, locks, panels |
| Fire alarm | Smoke and heat detectors, pull stations, horn/strobes, modules, panels (where in your scope and license) |
| Audio/visual and paging | Speakers, displays, wall plates, amplifiers |
| Nurse call, intercom, DAS | Stations and devices per legend |
Low-voltage symbols vary even more between designers than power symbols, so the AI reads the legend on each set rather than assuming a standard. See how AI electrical estimating handles legends and low-confidence detections, and the electrical symbols reference for common notation.
From device counts to cable and labor
Each device links to an assembly: the cable per drop, pathway (J-hooks, sleeves, conduit stubs), terminations, labeling and testing.
Example: 120 data drops averaging 150 feet to the IDF, plus 15 feet of slack and service loop per drop:
- Cable: 120 × (150 + 15) = 19,800 feet (19.8 boxes of 1,000-foot cable; buy 20)
- Terminations: 240 (both ends), plus patch-panel ports
- Testing and labeling per drop
Average run lengths can be measured from the plans by zone, and SparkQuote applies them to each device count.
Second example, cameras: 24 PoE cameras averaging 180 feet to the IDF, plus 15 feet of slack each: 24 × (180 + 15) = 4,680 feet, or 4.68 boxes, so buy 5. Keep camera cable on its own line if the spec calls for a different jacket color or cable category than the data drops.
Pathway: if the main J-hook route measures 1,800 feet and the spec calls for supports every 5 feet (example spacing; use your specification), the takeoff carries 360 J-hooks, plus sleeves at every rated wall crossing.
What goes into a per-device labor unit
Low-voltage labor is easier to check when each device's unit is split into the tasks behind it:
| Task | What it covers | What changes it |
|---|---|---|
| Rough-in | Box or mud ring, pathway to the ceiling, pull string | Wall type, new vs. existing |
| Cable pull | Pulling from the telecom room to the device | Run length, ceiling type, bundle size |
| Termination | Jack at the outlet, port at the patch panel | Cable category, shielded vs. unshielded |
| Test and label | Certification test, labels at both ends, report | Spec requirements, test equipment |
| Dress and trim | Cable management in the rack, faceplates | Rack density, owner standards |
Keep the split in your assembly and you can see, after the job, which task ran over.
System-specific notes
- Access control depends on door hardware from Division 08. Check the hardware schedule for electrified locks, power supplies and REX devices before counting readers, and confirm who wires the lock.
- Fire alarm device counts come from the fire alarm plans, but final quantities often change after the fire alarm submittal. Price what's drawn, state the basis in the proposal, and note that changes from the approved design are extra.
- AV often lists owner-furnished displays. Carry mounting, cabling and termination, and exclude the equipment itself if the owner is buying it.
Measuring by zone
Measuring every cable individually is slow and rarely more accurate. Most low-voltage estimators split the floor into zones around each telecom room:
- Mark each IDF and MDF on the plan.
- Draw zones for the areas each room serves.
- Measure a few representative runs per zone along the pathway, including the vertical drops at both ends.
- Apply the zone average to every device counted in that zone.
The takeoff tools handle the measuring; the averages stay visible on the takeoff so the foreman knows what was assumed.
Built for how low-voltage contractors bid
- Per-device labor units, adjustable by ceiling type, height and building occupancy.
- Cable by zone measured from IDF/MDF locations.
- Equipment lists from the riser and schedules, priced from your distributor quotes.
- Proposals with clear inclusions (cabling, terminations, testing, documentation) and exclusions (conduit by electrical, permits, head-end programming if subbed).
Common low-voltage estimating misses
- Service loops and slack left out of the per-drop length.
- Plenum-rated cable priced as non-plenum in return-air ceilings.
- Testing and certification reports carried as part of termination labor instead of their own line.
- Firestopping at rated wall and floor penetrations.
- Labeling and as-built documentation required by the spec.
- Hard ceilings and existing buildings, where each drop takes longer than in open new construction.
- Owner-furnished equipment that still needs mounting, cabling and termination.
Electrical and low voltage in one estimate
Many electrical contractors carry Division 27 and 28 alongside Division 26. SparkQuote keeps them as separate systems within the same job, so you can price them together or split them into separate proposals when the GC bids them separately. The same labor-unit and pricing engine as our electrical estimating software applies to both.
Frequently asked questions
What is low voltage estimating software?
Software that counts low-voltage devices from drawings and prices the cable, pathway, equipment and labor for data, security, fire alarm and AV systems.
How do you estimate cable for data drops?
Count drops, measure the average run from each zone to the telecom room, add slack and service loops, multiply, and round up to full boxes or reels.
Can the same software handle electrical and low voltage?
Yes. SparkQuote handles both, which suits electrical contractors that also carry Division 27 and 28 scopes.
How many terminations does a data drop need?
One cable has two ends, so each drop is terminated twice: at the outlet jack and at the patch panel. Count patch-panel ports and jacks separately so both are priced.
What does low voltage estimating software cost?
SparkQuote uses the same plans as our electrical product, starting at $99 per month. See pricing.