ADAAmericans with Disabilities Act
The ADA standards for accessible design provide the baseline for clearances, reach ranges, circulation, and sanitary spaces. ILS adopts ADA technical specifications as the foundational layer of the evaluation grid.
Methodology
How the standard evaluates a residential project.
The ILS methodology is built in three structural layers. The first two are public technical codes. The third is a proprietary residential framework. All three are applied to every certified project.
Layer 01
/ Code 01
/ Code 02
/ Code 03
International codes as the technical base.
ISO 21542International Standard
ISO 21542 is the international standard for accessibility and usability of the built environment. ILS aligns its criteria with ISO 21542 to ensure that certification holds technical equivalence across jurisdictions.
ANSI A117.1Accessible and Usable Buildings
ANSI A117.1 provides additional technical depth for dwelling units, including detailed specification of operable parts, controls, and adaptable features. ILS uses A117.1 for granularity in residential criteria.
Layer 02
The proprietary residential framework.
The international codes establish the technical baseline. Over them, ILS applies a proprietary residential framework that extends evaluation into areas the codes do not address directly: how spaces perform across the full life arc of an occupant, how a home adapts to events that arrive after handover, and how design choices made today affect asset value in two decades.
The framework was developed across two decades of field practice in residential evaluation, adaptation, and certification. It is the analytical layer that converts a code-compliant project into a long-term livability assessment.
The proprietary framework covers eight evaluation domains, each scored independently and consolidated into the ILS composite score:
- Approach and entry. The route from the street to the primary entry, including grade transitions, surface conditions, lighting, and shelter.
- Circulation. Internal horizontal circulation, vertical circulation, door clearances, and corridor widths under occupied conditions.
- Sanitary spaces. Bathrooms, powder rooms, and adjacent areas evaluated for accessibility, adaptability, and pre-equipment for future intervention.
- Sleeping spaces. Bedrooms evaluated for adequate clearances, reach ranges, and adaptability for caregiving or mobility-assisted occupancy.
- Food preparation. Kitchen layout and equipment positioning for usability across reach and posture ranges.
- Environmental controls. Lighting, acoustics, temperature controls, and the sensory environment.
- Outdoor and shared spaces. Patios, gardens, pools, parking, and shared circulation for multi-unit projects.
- Future readiness. Pre-equipment for vertical circulation, grab-bar reinforcement, smart-home integration, and caregiver provisions.
Layer 03
Evaluation, scoring, and level determination.
Every certified project is evaluated against the published criteria for each of the eight domains. Findings are categorized as meeting, partially meeting, or not meeting each criterion. The criteria are weighted within their domain, and the domain scores combine into the ILS composite score.
The composite score determines the certification level. Silver, Gold, and Platinum thresholds are published and fixed. They are not adjusted per project. The level a project receives reflects measured performance against the standard at the time of evaluation.
Where a project falls short of a target level, the technical report identifies the gap explicitly. Where the gap can be closed through adjustment, the report specifies what would be required to reach the next level. The standard does not negotiate criteria.