The calculation is performed for full retrofit of existing houses in the WUI and for new houses that will be built during a planning period. Let N’(h,t) denote the number of new homes added to the sample community per year going forward, and C’(h,t) denote the incremental cost to satisfy the National WUI Guide for new construction, for hazard level h and new home archetype t. Then the annual marginal cost per year at the community level for new construction can be estimated as:
C = Sh St N’(h,t) C’(h,t)
(2)
3.6 Community costs for National WUI Guide Chapters 4 and 5 The community may also incur costs to satisfy the National WUI Guide because it calls for considering WUI hazard in land-use planning. Doing so entails evaluation costs and possibly changes to development patterns that could raise or lower tax revenues, costs or savings from vegetation management, and costs for water supply, access and egress route construction and maintenance, developing and maintaining areas of refuge, fire protection services, power transmission and distribution, and intangibles such as the preservation and access to wildland spaces. The National WUI Guide provides a wide variety of guidance with many possible cost categories. The leading ones appear to include: 1. Planning: policy analysis and development plans (Sec 4.2.1) 2. Tax consequences from land-use constraints (Sec 4.2.2) 3. Enhanced access and egress routes and planned areas of refuge (Sec 4.2.3) 4. Enhanced water supply for firefighting (Sec 4.3.1) 5. Undergrounding power lines and non-combustible poles (Sec 4.3.1) 6. Buses, watercraft, and emergency communication (Sec 4.3.2) 7. Firefighting response planning (Sec 4.3.3.2) 8. Evacuation planning and resourcing (Sec 5.2.1) 9. Emergency communication equipment, planning, and training (Sec 5.2.2) 10. Public education development and implementation (Sec 5.3) Planning. Some of these cost categories cannot be estimated. The National WUI Guide’s recommendations for policy analysis and development planning do not seem to explain clearly enough for cost estimation purposes the planning products that municipalities, Indigenous, provincial, and territorial governments would implement to follow the Guide. For this cost category, the project team estimates order-of-magnitude costs considering WUI planning as a reasonable fraction of overall planning. See Chapter 4 of this report for our rationale and findings on this and all subsequent items. Taxes. Tax consequences are estimated considering the possibility that the National WUI Guide will affect construction prices, hinder or promote development, and thereby reduce or increase tax revenues in proportion to the change in development expenditures. See Chapter 4 for our rationale and findings. Access and egress routes. Costs of paving unpaved neighbourhoods and of adding access and egress routes probably dominate item 3. Costs are taken from the available literature on a per-route or per-household basis, rather than attempting to estimate quantities for every community or for sample communities. The project team observes pavements and sufficiency of access routes for each sample building and draws statistical information from those observations on the likelihood that a community will have to pave or improve access.
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