LHA size criteria: other families' children, foster placements and the additional bedroom

[MaxGhenis]

The LHA size criteria (LHA_allowed_bedrooms for Universal Credit, housing_benefit_LHA_allowed_bedrooms for Housing Benefit) have three gaps. Found while working on #2008 / #2010.

1. Other families' children are not counted

bedrooms_for_children counts only the claimant's own benefit unit. The household head's family counts non-dependants (UC) and occupiers (HB) from other families only if they are aged 16 or over.

• UC. The extended benefit unit includes "any person who is a non-dependant" (UC Regs 2013 Sch 4 para 9(1)(c)). Para 9(2)(g) excludes only "a child or qualifying young person for whom no-one in the renter's extended benefit unit is responsible". A non-dependant is responsible for their own child (reg 4(2)), so that child is a non-dependant and counts under para 10(1)(d)-(f), sharing with the renter's children. A lodger's or joint tenant's child does not count: the lodger is outside the extended benefit unit (para 9(2)(d)), so (g) excludes the child.
• HB. Reg 13D(3) counts "occupiers": everyone who occupies the dwelling as their home except a joint tenant outside the claimant's household (13D(12)). So non-dependants', boarders' and lodgers' children count. DWP's LHA Guidance Manual (paras 2.030-2.031) lists non-dependants, boarders and sub-tenants as occupiers, and excludes joint tenants outside the claimant's household.

2. Foster children get a bedroom; foster parents get no additional bedroom

bedrooms_for_children counts every member under 16, including a child flagged is_looked_after_by_local_authority. In law:

• UC. A foster child is in no one's extended benefit unit (para 9(2)(c) and 9(3); reg 4(6)(a)). The renter who is a foster parent, or an adopter with a child placed, gets one additional bedroom (para 12(4)-(5), (9)(b)) and is excepted from the shared accommodation rate (para 29(9A)).
• HB. A child placed with the claimant as a foster child or for adoption does not occupy the dwelling (reg 21(3)). The claimant is a "qualifying parent or carer" (reg 2(1)) with one additional bedroom (13D(3A)(b)), and is not a young individual.

lha_renter_has_non_dependant also treats a looked-after child under 16 as a non-dependant, since neither child test counts them. That wrongly takes a single foster parent under 35 out of the shared accommodation rate.

3. No overnight-care bedroom

UC Sch 4 para 12(A1), (3), (9)(a) and HB reg 13D(3A)(a), (3B) give one additional bedroom when the renter, a member of the extended benefit unit (HB: any occupier) or a foster child receives a qualifying disability benefit and has non-resident carers who regularly stay overnight. The model has no input for that.

The model also has no input for an approved foster parent between placements (UC para 12(5); HB reg 2(1)), or for a child placed for adoption (UC reg 4A(1)(c); HB reg 21(3)(b)-(c)).

Also: UC reg 2's "attendance allowance" includes armed forces independence payment. shared_accommodation_exception_benefits (para 29(5)) omits it.