142.22 A unit can carry only one more PP during its APh (RE: 5.73) than its IPC (EXC: two SMC’s may combine to carry 3 PP’s).
155.2 TRAVERSING STAIRCASES: Movement up or down building levels within a building hex now costs only one MF per level moved.
155.11 SINGLE-STORY HOUSE: All single hex buildings which do not contain a staircase symbol are considered level one obstacles to LOS and cast a one hex blind zone for LOS to or from a higher level. All units in such buildings are considered at ground level.
155.12 TWO-STORY HOUSE: All multi-hex buildings which do not contain a staircase symbol are considered level 1½ obstacles to LOS and cast a one hex blind zone for LOS to or from a higher level despite also having another vertical level in each hex besides the ground level in the form of a 1st Level capacity. All buildings of this type have an inherent staircase present in each hex. Units on a 1st Level counter are considered to be at level one, even though the building itself may be only a level 1½ LOS obstacle. Normal upper building level rules (57 & 125) apply. A 1st Level counter is treated the same as a 2nd Level counter except for the difference in elevation.
155.13 MULTI-STORY BUILDING: All buildings containing a staircase symbol are considered level 2½ obstacles to LOS and cast a two hex blind zone for LOS to or from a higher level. Such buildings contain both a 1st Level and 2nd Level capacity in each hex in addition to the ground level. Such buildings have no inherent staircase other than those represented by the white staircase symbol.
155.14 3RD LEVEL STRUCTURES: Level 3½ obstacles to LOS and 3rd level capacity are created only by SSR and are identified thereafter by placement of a 3rd Level counter on the appropriate hex(es).
(and also something to consider when considering enteringa single-story wooden house....)
170.7 CELLARS: A fully-tracked AFV which is neither CE, OT, nor carrying passengers may move into a single story wooden building at a cost of 4 MP’s plus an immobilization check (144.8), and in so doing creates a wooden rubble counter in that hex, if the AFV rolls a 6 on the colored die of the immobilization check, the AFV has fallen through the floor to the cellar and is replaced by a wreck. The AFV crew would roll normally for survival. Cellars have no other use in the game.
170.71 An AFV may not move through a rubble hex containing an immobilized or wrecked vehicle of any type. An immobilized AFV in a rubble hex may not change its VCA or TCA.
170.72 Any non-berserk infantry unit in a wooden building hex rubbled by the entry of an AFV is automatically broken after resolution of any overrun attack, and must rout from that rubble hex in the next RtPh or be eliminated. Heroes and berserk units must also leave the rubble hex in the RtPh, but are limited to a one hex move. They are not broken/wounded. An already broken unit would be treated as per 142.312.
Another aspect to consider in this scenario is:
161 Fortified buildings
161.1 Fortified buildings belong to the fortification category. No counters are used to indicate fortifications of this type. Only buildings can be fortified and only by SSR.
161.11 The number of fortified building levels is specified by SSR. If the specific location of such buildings is not specified, they must be selected and secretly recorded prior to the start of play. Buildings cannot be fortified during play. A fortification is not revealed until an enemy unit attempts to enter it, or it is fired on with a result which would be different due to the increased TEM.
161.12 In DYO scenarios all levels in a given hex of a multi-level building may be fortified, but only if all lower levels of that building are fortified. Improvements must be made, in any one hex, from the ground up. Thus, a fortified first level is possible only if the ground level directly below is also fortified. Improvements, or the lack thereof, in adjacent hexes of the same building do not affect this. Except as specifically modified below, fortifications are treated identically to other buildings.
161.2 Movement into a fortification is a function of whether or not the moving unit is friendly. Since the fortification is neutral, “friendly” is determined by which side’s forces occupy, or were the last to solely occupy, the building level in question.
161.21 Enemy infantry units may not enter a fortification hex during any phase so long as an unbroken, unpinned enemy squad (not just its equivalent in unbroken HS’s) is inside. Units which unknowingly attempt to advance into a fortification hex occupied by an unbroken, unpinned enemy squad lose their APh capability for that turn and must remain in their present hex.
161.3 A unit in a fortification enjoys defensive advantages with respect to both incoming fire and CC.
161.31 The TEM for a fortification is +4 for a fortified stone building and +3 for a fortified wooden building. Should a CH occur, the modifier becomes -4 or -3 respectively as per 109.4. HE fire vs a fortification on the Building target type is eligible for an additional +1 TEM.
161.32 The initial turn’s CC in a fortification is not resolved simultaneously. The defender executes his attack(s) first, and only the surviving attacker(s) may attack in return. Should a melee develop, the defender loses this advantage during subsequent CC rounds even if the attacker is reinforced by new entrants into the hex.
161.4 A fortification differs from a normal building in that AT/INF Guns ≤ 76mm may occupy the fortified upper levels of a multi-level stone building (RE: 57.6). Such a weapon must begin the scenario in place and cannot be moved from either that hex or that level during play. The minimum distance such a gun can fire at a lower target is equal to the difference in levels between the target and the firer. Other types of ordnance may occupy the ground level of a fortified building but may not fire at aerial targets or use indirect fire.
161.5 FIRE: All attempts to start a fire in a fortification or to have a fire spread to an adjacent fortification are penalized by a -1 DRM.
Didn't want to get to specific but you can see that things change a little bit when you start playing GIA, there's more to consider than just fire and move...
Bill