OK to get things done fast and effective we will do it this way:
Building has Security rating
Additional sensors increase the security rating by 1 for every 2 additional sensors implemented
If there is spider active, his perception adds to total
Players detection countermeasures count against Security rating. Only the lowest rating counts if more sensors are countered (chameleon with thermal damping 2 gives you only -2, if there is thermography in security cameras)
If you are trying to incappacitate the Security countermeasures of the building, Security rating is +3. If you try to takeover the full controll of the building, SR +6.
You roll standard infiltration roll.
AGI+Infiltration+anything that helps.
If you roll as team, use rules for teamwork, but the character with lowest infiltration dicepool rolls for the team, as he is most likely to be spotted.
If there are any maglocks and such barriers, they will be treated separatedly, but can raise alarm etc.
Applying ,multiple angles approach may result in some sensors or guards being turned off (i.e. by hacking, sniping, jamming, magical/spirit support etc.)
Security rating of the building may be guessed with Security design knowledge. Basic security rating is thresshold, any net hit above gives you more informations. In this case, AR plans and informations gives you +2, Home ground applies and teamwork is allowed for those who posess necessary
knowledges (Security design, Hardware/Sensors, Architecture etc...depends on what you are able to defend

)