Comparison

DALC vs Building Start

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

DALC

This tool helps engineers, architects, designers, and contractors accurately estimate air leakage from ductwork. It simplifies determining pass/fail for duct air leakage tests and allows combining multiple duct sections for total leakage calculations, adhering to industry standards.

Highlights
  • Estimate ductwork air leakage
  • Determine DALT pass/fail
  • Combine multiple duct sections
  • Calculate total allowable leakage
  • Provides suggested leakage classes
  • Compliant with industry standards
Features
Read full description

This simple to use but effective application is provided by the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA). This tool allows engineers, architects, designers, and contractors to easily and accurately estimate the leakage of air from ductwork. It also allows a quick and easy way to determine the pass/fail mark for properly specified Duct Air Leakage Tests (DALT). Users can combine multiple sections of ductwork that vary by size and shape to calculate a total allowable leakage. The application uses the method outlined in SMACNA’s HVAC Air Duct Leakage Manual, and provides suggested leakage classes from SMACNA’s latest edition of the manual. The method used is compliant with ASHRAE 90.1, IECC, IGCC Version 2, IMC and the UMC.

About

Building Start

This platform digitizes field testing for construction and engineering projects. It allows for centralized test plan creation and offline execution on field devices, synchronizing data back to the cloud upon completion.

Highlights
  • Centralized test plan authoring
  • Push test plans to field devices
  • Offline field testing capabilities
  • Data synchronization to cloud
  • Digital capture of construction projects
  • Support for TAB, Building Startup, Commissioning, Energy Audits
Features
Read full description

Building Start is a field services platform used in construction and engineering to perform centralized test plan authoring and management and push the test plan from the cloud to field devices to perform on-site field testing digitally. Once a field technician has been assigned a project, they can receive the project on their field device and perform the test plan and responses offline and synchronize them back into the cloud when they complete their work for the day. Building Start is widely used in the construction industry with over 30,000 construction projects digitally captured in such efforts as Test, Adjust & Balance (TAB), Building Startup, Building Commissioning (LEED, Green Building,etc) and Energy Audits.

Screenshots

DALC4 screens
Building Start4 screens

Verdict

The call

The clearest difference is rating: Building Start at 3.4 against DALC's 2.2. Building Start also leads on review sentiment (50% vs 15%). DALC's advantage is update cadence (every 2 weeks vs monthly) and ratings volume (26 vs 8). On price, ads, in-app purchases and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Building Start holds the better App Store score, 3.4 against 2.2. Both are backed by a comparable volume of ratings — 26 and 8 respectively. Written reviews point the same way: 15% of DALC's written reviews are positive against 50% of Building Start's.

UpkeepUpdate frequency

DALC ships an update every 2 weeks, Building Start monthly. The most recent releases landed on October 8, 2026 and September 24, 2026 respectively.

Scorecard5 real differences · 5 level
DALC versus Building Start: the parameters behind the verdict, then further details
ParameterDALCBuilding Start
PriceFreeFree
Rating2.2 (26 ratings)3.4 (8 ratings) — better
Positive reviews14.8% of reviews50.0% of reviews — better
Number of ratings26 — better8
Update frequencyEvery 2 weeks — betterMonthly
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS6.0 — better15.0
Further details — not scored
Size10 MB12 MB
Age rating4+4+
DeveloperSHEET METAL CONTRACTORS NATIONAL ASSOCIATION, INC.Building Start

Customer experience

DALC

All ratings26 ratings
Positive19.2%
Neutral19.2%
Negative61.5%
Written reviews27 reviews
Positive14.8%
Neutral22.2%
Negative63.0%

Building Start

All ratings8 ratings
Positive62.5%
Neutral0.0%
Negative37.5%
Written reviews6 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

In-app purchases

None

DALC

No in-app purchases

None

Building Start

No in-app purchases

Questions

Is DALC free?
DALC is free to download, with no in-app purchases.
Is Building Start free?
Building Start is free to download, with no in-app purchases.
Which has better reviews, DALC or Building Start?
Building Start is rated higher. DALC averages 2.2 out of 5 from 26 ratings, while Building Start averages 3.4 from 8 ratings.
Do DALC or Building Start have ads?
Neither DALC nor Building Start shows ads.
Which is updated more often, DALC or Building Start?
DALC ships an update every 2 weeks, and Building Start monthly. Most recently, DALC was updated on October 8, 2026 and Building Start on September 24, 2026.

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